Hydrus Axis 98 Whitewater Inflatable SUP Review | 2024

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The Hydrus Axis 98 whitewater iSUP is ideal for shredding river runs of all difficulties.

Hydrus Axis 98 Whitewater iSUP: Overview

The Hydrus Axis 98 (and the slightly smaller Axis 88) is the latest design from Idaho-based Hydrus Board Tech. The Axis 98 is a whitewater-specific river SUP that’s built to ride wave trains, punch holes, carve eddies, and surf on the fly. Hydrus has been making whitewater SUPs (both composite and inflatable) since they started shaping their own boards over a decade ago. The Axis 98 is a culmination of this design experience, materials experimentation, and the experience that only whitewater paddlers can bring to the drawing table. Whether you are just dipping your toes into river paddling and whitewater or you are charging Class IVs, the Hydrus Axis 98 is our top recommendation.

— Hydrus Axis 98 Summary Ratings and Review —

Hydrus Axis 98
  • Construction & Durability
  • Features and Versatility
  • Stability
  • Speed
  • Maneuverability
  • Tracking

Overall Score

The Hydrus Axis 98 is a specialty whitewater iSUP designed for paddlers of all skill levels.


  • Triple layer composite materials give the Axis 98 leading stiffness, durability, and a truly unique look.
  • Interior welded seams eliminate the worry of glue degradation for better longevity.
  • Double layer rails and rail reinforcement strips provide even more abrasion resistance.
  • The large continuous rocker profile keeps the Axis 98 extremely maneuverable and able to navigate whitewater river features.
  • Quad fin setup and 8 included fins allow you to customize the Axis 98 for your terrain.
  • Standard US and Two-Tab fin boxes allow you to customize your fin setup even further.
  • Water release wedge provides better speed and cleaner release for surfing.
  • All Hydrus iSUPs carry a Lifetime warranty.


  • Compared with many of the other boards we have reviewed the Axis 98 is fairly slow on flat water, but it is a specially-designed whitewater SUP, so that’s not necessarily a bad thing.
  • At 29 lbs, it is a little heavy, but this also gives you more momentum when working through sticky river features like crashing wave holes.

Construction and Durability

The Hydrus Axis 98 uses unique materials and high-quality construction techniques to improve stiffness, durability and longevity.

Hydrus Axis 98 iSUP review
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The Axis 98 has welded interior seams, double-layer rails, and extra rail reinforcement strips to keep you afloat even if you need to bump and rub your way down the river.

Hydrus Board Tech has been developing paddleboards, both composite and inflatable, for over a decade. Their constant testing, innovating, and willingness to look at board design and construction from different angles has really set them apart and given them a reputation for high-quality, high-performance products.

Everything about the Axis 98 was designed for durability on the river. Even the deck pad takes a turn from the diamond-groove pattern found on the Joyride XL and Paradise iSUPs that works so well with bare feet, and opts for a high-traction crocodile texture that is more durable, but just as grippy, when paired with protective footwear for whitewater paddleboarders.

The deck and hull are made of a triple-layer composite material. There is a layer of aramid fiber (better known by the brand-name Kevlar) sandwiched between a layer of black PVC and clear PVC. This is actually what gives the Axis 98 its gray color. Rather than dying the outer PVC layer, the white aramid fibers and black PVC layer blend together to create a metallic gray tone in a sort of optical illusion. The top and bottom layers are adhered to a knitted fabric that forms the internal drop stitch structure to keep the board flat (rather than round) and rigid.

The interior seams of the board are heat welded together. This fuses the layers of material into a single piece of PVC rather than using a chemical adhesive. Welded seams have better durability and longevity because the sections are physically bonded into a single piece. The outer rail layers and rail reinforcement strips are adhered to the outside of the board to add another layer of material for even better durability and rigidity. iSUPs with large amounts of rocker may be prone to twisting if not built correctly. The Axis 98 eliminates this concern with the use of a wide PVC stringer that runs the length of the board to keep the rocker true and prevent twisting.

If you add this all together you get an inflatable SUP that is built to take the bumps, scrapes, and impacts of whitewater paddleboarding, and to keep taking them for a long, long time. You also get the stiffest inflatable paddleboard we have tested to date.

In our static bend test, we suspend boards between a seven foot gap, and place a 170lb weight right in the middle. We measure how far the boards deflect at both 15 PSI and their maximum internal pressure (up to 20 PSI). The Axis 98 topped both of these charts. At 15 PSI it deflected just 1 inch, but at the maximum 20 PSI the same 170lb weight bent the Axis 98 just 7/8ths of an inch. For perspective, our overall average for this test at maximum pressure is nearly twice the amount of bend shown in the Axis 98 (1.675 inches).

BHydrus Axis 98 iSUP review
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At 20 PSI the Hydrus Axis 98 has taken the lead for our stiffest board tested.

Our bend test is a great way for us to put a numerical value on stiffness to make easy comparisons, but how does the Axis 98 feel on the water? We’ve certainly had boards in the past that felt better or worse once on the water than what their bend test results would indicate.

Stepping onto the Hydrus Axis 98 is like stepping onto a hard board. Jumping up and down on the Axis 98 created no perceivable flex to me, or in our photographs. It is an insanely stiff iSUP both off and on the water. That stiffness will translate to better performance for stability, speed, and maneuvering – all of which are critical for whitewater paddleboarding.

Hydrus Axis 98 iSUP review
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On the water I could not get the Axis 98 to have any noticeable flex – even when jumping up and down.


Length9’ 8”
Max Capacity350 pounds
Board Weight30 pounds
Kit Weight
(SUP & accessories)
38 pounds
Buying Info
List Price$1395.00
Warranty10 years
Returns period30 days

Features, Accessories and Versatility

The Hydrus Axis 98 is a specialty iSUP. It’s designed specifically for river and whitewater paddling. Because it is a specialty board, there aren’t quite as many features as you’d see on an all-around paddleboard like the Hydrus Joyride XL.

Hydrus Axis 98 iSUP review
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Hydrus Axis 98: 9’8” long, 35.5” wide, 6” thick, 8.5” of nose rocker, 350 lbs weight capacity
Hydrus Axis 98 iSUP review
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The nose has a padded grab handle, inflation valve, and medium-size 6-poin D-ring cargo area.
Hydrus Axis 98 iSUP review
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The tail has a raised kick pad with a raised center indexing rail. There are also two leash anchor points.
Hydrus Axis 98 iSUP review
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The deck pad has a crocodile texture that still offers great traction, but is more durable than diamond groove pads to hold up better against river shoe tread.
Hydrus Axis 98 iSUP review
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The center handle and two front handles are both padded with a neoprene sleeve.
Hydrus Axis 98 iSUP review
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The near-iridescent gray color is the result of the combination of the aramid fiber layer and black PVC layer showing under the outer clear PVC layer.
Hydrus Axis 98 iSUP review
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The raised kick pad and center indexing pad give you excellent fore-aft control of the board for quick turns and surfing.
Hydrus Axis 98 iSUP review
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The water release wedge reduces the surface tension at the tail of the board to help increase board speed, particularly surfing.
Hydrus Axis 98 iSUP review
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The Axis 98 and Axis 88 have a memorial graphic for Hydrus co-founder Nick Zawadski who passed away in 2021.

The Hydrus Axis 98 has a function-first design specifically for whitewater paddleboarding. The deck has a medium-sized cargo area that’s large enough to hold your necessities for the day, plus some additional safety equipment, but there are no other cargo or accessory storage features built into the board.

The inflation valve is at the nose of the board, rather than the tail, to make room for the kick pad to be placed all the way at the end of the tail. This gives you even more vertical range when stepping back to lift the nose higher out of the water, and you can more easily make minor adjustments to your trim.

The deck pad is a flatter crocodile texture rather than a deeper diamond groove texture. The shallower tread still provides lots of traction, but holds up better to the protective footwear that whitewater paddlers use.

In addition to the center handle, there are two more padded handles on the deck of the board. I refer to these as “O.S.” handles – because when you need to use them it’s usually around the same time you’re thinking “Oh Sh!t.” Sometimes you just need to get low and hang on for the ride!

The Axis 98 also has padded nose and tail handles. In addition to making it easy to partner-carry the board, these handles also give you more control points if you do find yourself swimming next to your board.

What really differentiates the Axis 98 is its shape. At just 9’8” long, but 35.5” wide, the Axis 98 is very stable and extremely maneuverable. It also has a significant amount of both nose rocker and tail rocker in a mostly continuous shape. There is a little bit of a flat section around the standing area rather than being a totally smooth curve. Because the Axis 98 sits between a fully-continuous rocker profile and a straight kick-rocker profile you get the best of both without any drawbacks that I’ve noticed. You can easily adjust how high your nose is riding with small changes in foot placement or weight distribution, like you can with a continuous rocker board, but you don’t have the sudden tilt sensation that you get when stepping onto the tail of a board with kick-rocker only. Likewise you do get some of the speed and stability benefits of a flatter board with kick-rocker only, but you still maintain the ability to turn on a dime like with a continuous-rocker board.

Hydrus Axis 98 iSUP review
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The Axis 98 has 8.5” of nose rocker with a mostly-continuous rocker outline. You can see the difference here between the Axis 98 and the Joyride XL..

On the bottom of the board there is a tow/anchor D-ring on the nose, and four fin boxes on the tail. Two of these fin boxes are standard US Fin boxes, and two are a newly-designed Air7 Two-Tab/Click Fin/FCS style that include a spring-loaded ball bearing to help retain the fins without needing the grub screws. I still use at least one grub screw on each of the front fins, though.

Hydrus Axis 98 iSUP review
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The Axis 98 does not include a paddle, but the Hydrus carbon fiber/Armalight paddle is great for whitewater.

In the kit with the Axis 98, you also get 8 fins (4 different pairs) to let you customize your tracking and maneuverability performance. I’ll get more into that in those sections below. The Axis 98 also comes with a repair kit, double-action pump, Hydrus Mothership bag, and a grub screw key.

The Axis 98 (and the Axis 88) does not include a leash. River paddling requires a specific type of quick-release leash that is worn on your torso as a safety precaution. Typical ankle and calf leashes should never be worn on rivers. As a whitewater-specific iSUP in most situations it is far safer for the paddler to not wear a leash if they do not have a quick-release leash available.


Hydrus does not automatically include a paddle with their paddleboards. Paddles are as much of a personal choice as selecting a board, so they want to leave that decision up to you. They do make a 3-piece carbon fiber/composite paddle that works excellently for whitewater (and flatwater).

Hydrus Axis 98 iSUP review
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The Hydrus carbon fiber paddle is lightweight and durable with a medium-small blade.

The Hydrus three-piece adjustable paddle is made with a variety of different materials. The shaft and the core of the blade are made with carbon fiber, however the blade gets additional layers of Hydrus’s proprietary Armalight composite material. Armalight was developed to be a more durable alternative to traditional composite layups, while still keeping the blade lightweight and stiff. After several very shallow runs on rocky rivers in Class II-III whitewater there are a few signs of use on my Hydrus paddle, but not many.

The handle section is made of molded fiberglass and features an anti-twist indexing groove, blank measuring scale, and molded finger divots in the palm grip. The indexing groove and molded divots make it nearly impossible to accidentally use this paddle backward. The blank height scale allows you to easily remember where to set your paddle, but doesn’t try to guess at what length you should use. Every paddler is different on how long they like their paddle.

The Hydrus paddle is durable and stiff, the blade is moderately large at 96 square inches, and the overall weight is 26 ounces. While it’s not the lightest paddle we’ve tested, it’s definitely not the heaviest. The stiff paddle shaft and larger blade face let you put a significant amount of power into your stroke when you need it, and the rectangular shape and dihedral ridge make it comfortable to use all day.

Check the Best Price on the Hydrus Paddle


At 35.5” wide, the Axis 98 screams stability, but when comparing it directly to other iSUPs like the Joyride XL (11’6” x 34”) it may feel less stable overall. The shape and size of the Axis 98 make it very reactive to user input, which can feel less stable compared to a board that is less reactive.

Hydrus Axis 98 iSUP review
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The Axis 98 is very stable flat and on its edge, but has a very different feel compared to a larger board like the Joyride XL.

When you are standing on the Axis 98, it feels extremely stable. It’s wide, it’s incredibly rigid, and it keeps its width through a large section of the board. If you were to paddle it side-by-side with a similar board that’s a little longer and flatter, like the Joyride XL, you would feel that the Axis 98 isn’t quite as stable as the Joyride XL. This is due to a few different reasons.

First, the overall volume of the Axis 98 is smaller than the Joyride XL. Less volume typically translates to a less-stable feel. The next difference is the length. While many people concentrate solely on the width of a paddleboard to critique its stability, they are missing out on a huge piece of the puzzle. The extra length of the Joyride XL not only increases its volume, but also resists turning in the water and has more surface area touching the water when it’s on its edge. Lastly, the rocker profile of the Axis 98 means there is far less of the board touching the water at any given time compared to a flatter iSUP. Less contact means less stability.

However, the Axis 98 is still very stable. The best way to describe the feeling of paddling the Axis 98 is “reactive.” The Axis 98 is very reactive to user input, so when you step back on the tail, it lifts the nose quickly. When you weight one side or the other, it gets right up on its rails to help you carve a turn.

The Axis 98 is on the heavy side at just over 29 lbs. Once you put the board on the water, though, this extra weight turns into a benefit. Heavier boards have more inertia, which means they resist tipping better. When rocking the Axis 98 from side to side it moves and resurfaces the rails smoothly and with control rather than giving you a bouncy sensation.

The number and types of fins you use will also make an impact on the initial stability of the board. Using no fins, or just the smallest fins, will result in less stability, while using all of the largest fins will give you more stability as they help the board resist rolling side to side as easily.


Short, wide, and lots of rocker are about as far from the desired recipe for speed as you can get. The Axis 98 isn’t built to be super fast, but it can still put some respectable speeds on the score board.

Hydrus Axis 98 iSUP review
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The Hydrus Axis can get up to a high speed for short distances, but directional control becomes an issue.

Speed control is a critical component to paddling whitewater, but top speed is not. To be blunt, the Axis 98 is not a fun SUP to sprint with. It does tend to push a little water and its size and shape make it hard to keep paddling in a straight line. Even with all of that, I was still able to get the Axis 98 up to a top speed of 5.3 MPH on flat water, though the average speed for a 100m sprint was only 4.7 MPH.

In our ¼ mile cruising-speed test, the Axis 98 averaged around 3.0 MPH, but that will depend greatly on your exact stroke cadence. We also measure the glide efficiency of each board. This tells us how far a SUP will move on a single stroke before it begins to slow down. The Axis 98 has a very efficient 1.8 board-lengths per stroke glide ratio, however it is important to remember that the Axis 98 is also very short compared to most all-around SUPs.

What is more important for whitewater paddlers, though, is how quickly the Axis 98 can accelerate. When we need to move from one side of the river to the other in the middle of a rapid, we want to know that we can actually do so with some degree of speed. Because the Axis 98 is so rigid, it responds very well to those critical first paddle strokes and accelerates quickly.

Maneuverability and Tracking

Maneuverability is where the Axis 98 shines brightest. At the same time the quad fin box allows you to dial in your own preferred balance of maneuverability and tracking.

Hydrus Axis 98 iSUP review
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The Axis 98 can turn nearly as quickly with forward sweep strokes as it can with reverse sweep strokes.

The Axis 98 comes with a variety of different fins to let you set it up for your own preferences. For testing purposes I used two 1” fins in the front fin boxes and two 4.5” fins in the rear fin boxes.

To test maneuverability we determine how many forward sweep strokes it takes to turn in a full circle from a standstill. The length and width of the board, how stable it is, the specific fin setup, and even the size of the paddle all play into this test to one degree or another, but the most important of these are the length of the board and the fin setup. With the Axis being shorter to begin with (only 9’8”) and having a significant amount of rocker in both the nose and the tail, the effective board length in the water is closer to 6.5-7’. The river-specific fins are all shorter and have smaller surface areas to allow better maneuverability as well. So it came as no surprise that the Axis 98 is able to essentially turn on a dime. It takes fewer than four forward sweeps to make a complete 360° turn with this “moderate” fin setup.

Swapping the 4.5” rear fins for the 3” rear fins would let the Axis 98 turn even faster, and swapping the front 1” fins for the 4” fins would slow it down.

Hydrus Axis 98 iSUP review
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Tracking is not the Axis 98’s strong suit, but can be adjusted by fin selection, body position, and paddle technique.

On the flip side, the same characteristics that make the Axis 98 so agile greatly reduce its ability to paddle in a straight line. With the same “moderate” fin setup (2 x 1”, 2 x 4.5” fins) the Axis 98 wandered off course by an average of 26° over the course of 10 paddle strokes on a single side. For shorter all-around iSUPs we usually see results in the 15-20° range.

By using some more advanced stroke techniques (like canted forward strokes or combination bow-draw forward strokes) you can keep the Axis 98 moving straight with just a little bit of effort. The first time I took the Axis 98 out on the water was for a moonlight lake paddle and I was actually greatly impressed with its flatwater performance considering it is a specialty whitewater iSUP.

Hydrus Axis 98 iSUP review
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The Axis 98 includes 8 fins. 2 x 1” keel-style fins and 2 x 4” surf-style fins for the front fin boxes, and 2 x 3” and 2 x 4.5” fins for the rear fin boxes.

The fins that come with the Axis 98 are designed to work in a variety of different conditions. For shallow water paddling, the 1” deep, 10” long keel-style fins and the 3” standard fins work well together to provide enough traction in the water to help you hold your line for short distances while staying low-profile enough to avoid catching rocks. Because the rear fin boxes are placed on the area of the board lifted by the tail rocker, they don’t reach as deep into the water. This lets you adjust how much you engage the fins by changing your position or weight distribution on the board. Putting more weight back engages the fins more and putting more weight forward lifts them slightly up.

In deeper water you can use the 4” front fins and rear 4.5” fins for maximum holding power. This is especially good for bigger water rivers where strong lateral waves and cross-currents can push you off your line easier. The larger fins combined with a little bit of speed control allows you to keep your course and cut across these features without getting spun or pushed around.

Because Hydrus uses standard US fin boxes for the rear and standard two-tab fin boxes for the front you have the option to get use some of the other thousands of fins available to really customize your performance. The front two-tab fin boxes have a spring-loaded ball bearing in them to help hold your fins in place without the need for a grub screw. However I still prefer to lock the fins in place using the built-in grub screws and included fin key. It only takes a few seconds to tighten and loosen, but adds significant security to the fins.

Hydrus Axis 98 iSUP review
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A shallow water setup with 1” fins in front and 3” fins in the rear.

Warranty and Customer Support

Hydrus Board Tech covers all of their inflatable SUPs with a lifetime warranty against any manufacturing issues (like seam leaks). Their paddles and bags are also covered by a lifetime warranty against defects, and their other accessories have a 60-day warranty. Hydrus also has a 30-day return period. As a small company, Hydrus values their customers highly and has some of the fastest and friendliest customer service I’ve experienced. When I first received my Axis 98 it was missing a few fins. I emailed them about the missing fins and I had a shipping notification in my inbox less than an hour later (followed up by a phone call). If you have any questions about Hydrus’s boards, paddles, or other products, you can contact them by email, web form, social media, and phone. When calling them you’ll often speak directly with the owner, Jason, and he loves to talk SUP and help people get on the right board.


The Hydrus Axis 98 is a specialty whitewater iSUP. It’s built with some truly unique materials and carries a lifetime warranty. Between its high-performance on the river, great customer service, and the great accessories included, the Axis 98 offers a fantastic value for anyone looking for a whitewater-specific SUP.

Overall Impressions/Review Summary

Hydrus Axis 98 iSUP review
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The Axis 98 is a river specialist that can take you from your first eddy turn to dropping into some serious gnar (or just some local “Class Fun”).

Brothers and Hydrus founders Jason and Nick Zawadski grew up paddling and surfing. They began shaping their own surf and paddleboards to meet their own performance needs and started Hydrus Board Tech in 2012 with the goal to create the best possible boards by experimenting with different materials and focusing on function-first shapes. The Axis 98 is Hydrus’s newest model. It’s also the last model designed together Nick and Jason together before Nick sadly passed away in 2021. The Axis 98 and 88 have a memorial graphic on their hulls to remind us to “Paddle Like Nick” – love what you do and be the paddler having the most fun on the water. The Axis 98 is an easy board to help make that happen. It’s built for advanced paddlers to charge hard into those Class IV’s, but is not so aggressive as to make it hard for newer paddlers to learn the basics on their local “Class Fun” rivers. It’s a high-performance river board built to last, and Hydrus’s lifetime warranty ensures that you’ll have fun on the river for years to come. I was incredibly excited for this paddleboard when it was announced, and it’s been living up to (and exceeding) my expectations. Whether you are new to whitewater SUP, looking to upgrade to something that can handle more action than your all-around board, or looking for the toughest whitewater board to tackle those technical first descents, the Axis 98 is up for the challenge.

Hydrus Axis 98 Whitewater iSUP FAQ

Can I use the Axis 98 on flatwater?

You can certainly use the Axis 98 on flat water, however it is not ideal for longer flatwater trips. The Axis 98 is designed for agility rather than tracking, so longer flatwater paddles are better suited for boards like the Hydrus Paradise or Hydrus Joyride XL.

Why does the Hydrus Axis 98 have so many fins?

The Hydrus Axis 98 is designed to work well in all river conditions whether they are shallow, technical creeks, or big water rivers. Having the right size and shape fins makes a huge difference in how a paddleboard will perform on the water. Hydrus understands this and included a variety of different fins to allow you to set up your Axis 98 to best meet your local conditions.

Does the Hydrus Axis 98 include a paddle?

The Hydrus Axis 98 does not include a paddle. However the Hydrus carbon fiber paddle is available at a deeply discounted rate when bundled with the Axis 98 (or any other Hydrus paddleboard), and it makes a great whitewater SUP paddle.

Does the Hydrus Axis 98 include a leash?

The Hydrus Axis 98 does not include a leash. River and whitewater paddleboarders must use quick-release leashes that are attached to your torso. These leashes come in a variety of different styles that all have their benefits and drawbacks. On Rivers (especially whitewater, but any river) it is safer to not wear a leash than it is to wear a standard ankle or calf-leash.

How long does it take to inflate the Hydrus Axis 98?

Using the included hand pump it takes about 10 minutes to inflate the Axis 98 to 15PSI. We recommend inflating to 20 PSI for best performance; we also recommend an electric pump for any iSUP to make the inflation process easier.

Is the Hydrus Axis 98 worth the price?

Yes. The Hydrus Axis 98 is a specialty whitewater SUP. It’s high-performing, built with high-quality materials and construction techniques, and includes a great set of accessories. It also has a lifetime warranty against manufacturing defects including seam leaks.

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