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Fluid™ 12 Backpack


https://www.mountainhardwear.com/fluid-12-backpack-OU5947.html OU5947


Lightweight pack ideal for fast-moving endurance athletes to day hikers. The low-profile design offers maximum range of motion while keeping essentials within reach. Includes an easy access hydration sleeve with convenient tube exits that you can route high or low, left or right.
$59.90 $80.00
Style# 1539931
product.components.activity: Running / Training, Backpacking / Hiking


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Features & Specs

  • Weight: - 14.1 oz. / 400 g. -
  • Reviewers rated this product: - True to Size -
  • Pack Capacity: - 732 cu. in. / 12 L -
  • Good For: - Running / Training -
  • Good For: - Backpacking / Hiking -


Lightweight pack ideal for fast-moving endurance athletes to day hikers. The low-profile design offers maximum range of motion while keeping essentials within reach. Includes an easy access hydration sleeve with convenient tube exits that you can route high or low, left or right.



  • Fabric Accent: Power Mesh
  • Fabric Body: 100D HT Ripstop Dobby Nylon


  • Apparel Fit: Equipment
  • Pack Weight Regular: 14.1 oz. / 400 g.
  • Pack Capacity Regular: 732 cu. in. / 12 L
  • Pack Dim Regular: 18 in x 10 in x 8 in / 44 cm x 24 cm x 20 cm
  • Pack Torso Regular: 16.0 in. - 22.0 in. / 41 cm - 56 cm
  • Pack Waist Regular: 25 in - 37 in / 64 cm - 94 cm


  • Soft, ventilated shoulder straps
  • Close fitting suspension with on-the-fly compression and venting channels to prevent overheating
  • Easy access hydration sleeve offers choice of routing tube over the shoulder or from lower pack, left or right
  • Top fleece-lined zippered pocket for safe storage of sunglasses, smart phone or other valuables
  • Zippered front pocket with key clip
  • Stowable webbing belt adds stability when needed
  • Two deep side pockets for water bottles or other gear
  • Stowable carry loops for ice axes or trekking poles
  • High visibility, safety reflective hits
  • Imported


Fluid™ 12 Backpack is rated 4.6 out of 5 by 9.
Rated 4 out of 5 by from Excellent!..except.. This daypack is super light, and fits very well. There's enough room for a day hike, or commute..you barely know it's on, unless you have significant weight in it. I also like that the bladder pouch is outside and independant of the main compartment, covered by the upper shoulder strap harness. This, however is strictly a fair weather pack. While the treated fabric may be water resistant, the top and main zippers are completely exposed. On a rainy day, there'd be water ingress. I would suggest to MH either a storable rain cover w/zippouch, or at a minimum zipper covers. So, if it's sunny or cloudy, excellent and highly recommended..
Date published: 2016-04-22
Rated 5 out of 5 by from Great day pack Extremely easy to wear and the color is great. I really enjoy the top pocket near the handle. I can put chapstick in there or camera cleaning pen. I like that the handleis not towards the back but more forward biased. The side mesh pockets are great, on a side note there are holes down there so don't put anything small in there. The only issue I've had is the pull ropes on the zipper are coming off slowly but surely. And a nice thing in the future would be to have a weather resistant version of this bag.
Date published: 2015-09-22
Rated 4 out of 5 by from Jack of all trades A great pack that has performed as advertised. I have used it to carry a 3 L bladder for a long, unsupported summer run. There was a bit of jostling of contents, but overall, it worked as you would expect a 12 L backpack to work while running--not formfitting like a running vest, but a lot more capable. Its strength is its versatility, and I think it will make an outstanding MTB and day hiking pack as well. My only critique is that I think it could use an extra set of compression straps to keep it together a little better while running. I'm 76" and 180 lbs, and the R was a bit on the small side. But I'm also a bit on the tall side.
Date published: 2015-08-10
Rated 4 out of 5 by from Alternate Use This bag is a perfect substitute for a "man purse". It's more practical than a messenger bag, blends in and it holds just enough. Great for plainclothes police work.
Date published: 2014-12-11
Rated 5 out of 5 by from Nice Bag Yo! I have many, many packs. This day pack has good suspension pulled tight to the torso, breathes well and can handle a good stretch with moderate weight. I am using it for cross-training (cycling and running trails). So far so good, I could get a warm-temperature overnight out of this pack... maybe multi-day but I am very lt-weight with equip needs and would not have a sleeping bag or tarp. good seals, good water beads during lt-rain.
Date published: 2013-06-11
Rated 5 out of 5 by from Take-along This Fluid 12 is perfect size and very comfortable. It fits just enough, snacks, liquids, extra layers and gadgets to make it a must take-along on all hikes and activities. I will be using it in the New England Winter also and I have no doubts that it will keep me with me especially once I start loading it up to its capacity with winter gear. LOVE IT!!
Date published: 2012-10-22
Rated 5 out of 5 by from more space than it meets the eye I've used this for running through the mountains of Canada's arctic, often I threw in some snacks, my climbing shoes(in case I found a boulder that needed climbing), towel(for glacier water ice baths), and a light sweater and water bottle. Holds everything without jiggling and bouncing to allow for miles to be conquered. It works amazing for cycling and day tripping too!
Date published: 2012-08-15
Rated 5 out of 5 by from Great Product Great product. I use it for biking back and forth to class when I only need to pack a few things and I like wearing it when I bike in general. Just to note, there is a sleeve for a water bladder :)
Date published: 2012-07-15
Rated 4 out of 5 by from Good little pack for cycling This pack kind of dissapears on a long ride. Very comfortable and not in the way. My only complaint is that the description makes it sound like a water bladder is included and it is not.
Date published: 2012-05-02
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