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Fluid™ Race Vest


https://www.mountainhardwear.com/fluid-race-vest-OU5390.html OU5390


State-of-the-art ultraruning vest pack. Designed to be as light as a layer of clothing but with the functionality of a small pack.

Past Season Color
Style# 1501621
product.components.activity: Running / Training


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Features & Specs

  • Weight: - 5.6 oz. / 160 g.
    5.8 oz. / 165 g. -
  • Reviewers rated this product: - True to Size -
  • Pack Capacity: - 175 cu. in. / 3 L
    175 cu. in. / 3 L -
  • Good For: - Running / Training -


State-of-the-art ultraruning vest pack. Designed to be as light as a layer of clothing but with the functionality of a small pack.

Past Season Color



  • Fabric Accent: Power Mesh
  • Fabric Body: HexWall Mesh
  • Body Fabric Content: 100% polyester


  • Pack Weight S/M: 5.6 oz. / 160 g.
  • Pack Weight M/L: 5.8 oz. / 165 g.
  • Pack Capacity S/M: 175 cu. in. / 3 L
  • Pack Capacity M/L: 175 cu. in. / 3 L
  • Pack Torso S/M: 16.0 in. - 19.0 in. / 41 cm - 48 cm
  • Pack Torso M/L: 18.5 in. - 22.0 in. / 47 cm - 56 cm


  • Cool, wicking mesh in contact areas on shoulder straps and backpanel
  • Comfortable, very low-profile, wide shoulder straps distribute weight effectively
  • Four easy access pockets of varying sizes on shoulder straps keep necessary items in reach
  • Essential race gear fits securely in super stretchy, zippered back pocket
  • Bungee setup allows for overloads and compression
  • High visibility, safety reflective hits on rear and front
  • Imported


Fluid™ Race Vest is rated 4.8 out of 5 by 5.
Rated 5 out of 5 by from Looks can be deceiving When I unpacked this, I immediately thought it would be too small. I felt the same after I tried it on and stuffed a bottle in the front right pocket. Then I went on a five hour trail run, and it was awesome. I had a 1.5 liter bladder in the back, a 20oz bottle in the front right, a bunch of gels and such in the other pocket. Even though the bottle angles back under your arm, it never bothered me while running like I thought it would. Also, the fit was secure. The vest did not jump around like my other racing vest. Great product for my needs. fyi, I am 5'9'' and 160 lbs. M/L vest
Date published: 2014-02-07
Rated 5 out of 5 by from Love this pack! I bought this to replace an older hydration pack I had from a previous job that required a lot of walking/hiking. I am so happy with my purchase for many reasons. 1. Compared with my other pack, this feels feather-light which is such a nice change. 2. The reflectors are useful for my dusk or dawn runs. 3. The many pockets hold my cell phone, music, pocketknife, and I still have room for more. I used the back cords to hold my gloves on my last run. 4. The pockets in the front are nice. My last pack only had storage on the back so whenever my phone rang or I wanted to change my music I had to take the whole pack off. 4. This pack is a nice alternative to wearing a water belt that bounces on your hips no matter how tight you cinch it. I wore a duty belt for years at my last job and I really don't want that feeling again. The only downside I can see is having to buy a small bladder. Since my kids have hydration packs I just borrowed one of their bladders so I didn't have to spend the extra money. If you look at the other water packs, they don't offer as many front pockets as this one does. I'm quite satisfied with my purchase. I bought the size small/medium which worked well for my 5'3, 110# frame. My husband might order one for himself; he's not getting mine!
Date published: 2014-01-29
Rated 4 out of 5 by from Light and Functional, but a little snug I'm not huge, 5'9" 195lbs, 42" chest, but the M/L fits snug and the 2 chest straps are maxxed out. I kind of feel like a fat guy in a little vest. However, when running, it feels like a second skin and it didn't move/slide at all on a 10-mile trail run. The back pocket holds a 50-oz Camelbak Antidote Reservoir (the 70-oz sticks out the top) with little room for much else. The pack has bomber construction like all MH products and the four front pockets are great for a cell phone, keys, ID, etc. This product is perfect for the normal skinny runner and for long day runs.Their other running vest, the MH Race Pack, has adjustable side straps and more capacity for only a few dollars more, so I'd recommend that for bigger runners or longer trips.
Date published: 2013-12-01
Rated 5 out of 5 by from Perfect I thought it was gonna be too small. It ended up stretching and conforming perfectly. Fells nothing like a backpack. Ran 13 miles the day I got it with 2 liter hydration bladder, I-phone, peanut butter and jelly sandwich, a bag of nuts, and still had the top 2 pockets empty and tons of space for a light jacket etc in the back. I'm 5'5'' 150lbs. If you're bigger than that I would get the med/large. Thanks Mountain Hardwear
Date published: 2013-09-16
Rated 5 out of 5 by from Fantastic super-light fast pack This is all I'm using for even extended all day hikes. I can fit 2 bladders with water and electrolyte/carb in the bladder compartment and plenty of room for extra light jacket etc in back. Nice cell phone pocket on front strap. Straps fit great with no hip belt to bother with. Nicely balanced Merely the best
Date published: 2013-06-28
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