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  • Wide-mouth opening with Slidelock™ closure is easy to fill and locks securely
  • Low-profile design rides flat in your pack
  • BPA-free polyethylene with silver-ion antimicrobial finish offers clean, taste-free drinking
  • Quick-release hose and shutoff valve make drinking and refilling easy

Made in USA.

View all Platypus Reservoirs

REI membership


Best Use Multisport
Reservoir Capacity (fl. oz) 101
Bite Valve Shut-Off Switch Yes
Wide-Mouth Opening Yes
Quick Disconnect Tubing Yes
Material(s) Polyethylene
Dimensions 17.2 x 8.8 inches
BPA Free Yes
Weight 6 ounces
Rated 5 out of 5 by from works great, less filling Bought this to replace an old camelbak that started tasting pretty funky. Took it out on a hike in my 40L Mountain Hardwear bag, and hardly knew it was there. The new low-profile shape does not cause the bump you typically feel with a regular designed bladder. I did have to change a couple things though. The plastic hanging strap would not work with the internal clip inside my bag to hang right, so I removed it and replaced with some paracord. Also had to change the bitevalve. The original one was too bulky, and did not flow well. Luckily, it is the same size as the camelbak valves, and was a 30 second job to swap. The changes were pure preference, and overall love the design. Highly recommended.
Date published: 2014-05-30
Rated 5 out of 5 by from awesome I started using this hydration bladder this spring on our training hikes for our trip to the Sierras coming next month. My wife and I both have nothing but good to say about this hydration bladder. First and foremost it is incredibly easy to both fill and clean. Also, neither has leaked even a tiny bit. Not to mention that I can put 100 oz of water in my pack and I hardly notice it is there in my opinion thanks to the flattened design of the bladder. There is only one small issue and that is you definitely have to find the sweet spot on the bite valve to get good water flow. Once you find it you are good to go. I Definitely recommend this to anyone.
Date published: 2016-05-19
Rated 5 out of 5 by from go with the big bag! I love being able to carry a full 3 litres of water with me on long day hikes, even though I often fill the bag up to just around 2 litres. Why not get a bigger bag for those times you need it -- or for when you want to carry more water weight for training purposes? Works well. Water comes out easily. No leakage. Happy with the way the bag fills and seals, as well as the length of the tube and the way the bite valve works, with the twist closure. (It would be nice if the reservoir came with a cover for the valve rather than having to buy that separately.) I appreciate the clip that comes with it, though I use a carabiner as well, higher up on my pack, to keep the tube in place. Easy to clean and keep clean.
Date published: 2016-01-11
Rated 5 out of 5 by from THE BEST!!!!! I will never hike without this! The capacity is perfect, the bite valve works well, once you find your sweet spot/bite and it is soooo easy to fill, clean and dry. I filled it and used it around the house to see if it leaked. I even stepped on it once, when it was about 2/3 full, nothing happened. I have even put it in my laptop sleeve and have taken it to work just to stay hydrated with filtered water from home. It is rare that a product exceeds my expectations, but this one does.
Date published: 2014-07-09
Rated 5 out of 5 by from Easy to use and works well! I can't believe I've not seen this before. This thing is AMAZING! It securely zips shut and doesn't leak. The opening is big enough that you can completely dry it out between uses and it's also big enough for you to put ice in it! Not only that, but it still clips in to my pack so I don't have to worry about gravity helping me out! This is by far one of the best investments I've made for doing field work.
Date published: 2014-05-28
Rated 3 out of 5 by from Bad design of new shutoff = broken shutoff I have an old 3L Platypus and have had no problems with it. My wife bought this one and it now has a plastic divider down the center of the reservoir which keeps it from bulging into a circle in your pack when filled. Pretty slick feature and definitely welcome. The mouthpiece shutoff has been changed on the new 3L though and now it is made of hard plastic which sticks out. Consequently, the plastic snapped off within a few weeks of owning the bag and now the mouth valve spits 270 degrees instead of the 150 or so it should. They ruined a previously good shutoff system. I wouldn't recommend this bag not because it's really bad, but because the old version is better. I care more about the shutoff than the rounded reservoir bulge in my pack. Photo - Old (low profile, softer plastic, flush design) shutoff on the top, new (broken) shutoff on the bottom
Date published: 2015-07-17
Rated 5 out of 5 by from Not as bulky as you think! I purchased this bladder over a year ago and still feels new. I fill up my 3L and slide it into my deuter packs, I loved how this bladder is not long and bulky, but its rather flat for 3L. it creates usable space behind the bladder sleeve in my packs. Never a leak, also flip it upside down before placing in my pack just to be sure. The quick disconnect its awesome, and when reconnecting there is a very positive "snap". never going back to other brands.
Date published: 2014-10-23
Rated 5 out of 5 by from Great Product! I have used my trusty MSR Platypus for years ~ I never leave home without it. Whether out for an early morning Summer hike or snowshoeing/backcountry skiing in the Winter, this has been an outstanding product. Thanks for a great product from a Northwest native!
Date published: 2016-01-24
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Will this work with the REI Crestrail 70 Pack?

Asked by: PrestonEsco
As of June 2016, we are estimating this item will be in stock in the next 30 days. The 3 liter Hydraulics Reservoir will fit in the Kestrel and the Ariel packs.
Answered by: REIservice
Date published: 2016-06-23

I recently bought this and have used it for a long hike. How do I clean the hose?

Asked by: LBP
The Platypus Cleaning Kit is the best choice for cleaning your Big Zip LP Reservoir. The kit comes with a brush for scrubbing your hose. Platypus will have step-by-step cleaning instructions on their site.
Answered by: REIservice
Date published: 2017-05-04

I have both an Osprey Exos 48 and REI flash 18.  I know it will fit the Osprey but will it fit the REI flash 18 if I only fill it 1.5L to 2L full?

Asked by: ongnoimay
Yes, you can carry this reservoir in a Flash 18. By not filling it full, you will keep the weight down, which will make it easier to carry in the stripped down Flash 18.
Answered by: REIservice
Date published: 2015-09-20

What is the tube made of?

Asked by: GaryB
The reservoir tube is made from polyurethane. The bite valve is made from silicone.
Answered by: REIservice
Date published: 2015-09-20

Will the 3 litre fit in the Osprey Atmos 65 AG ?

Asked by: Ddub59
Yes, this 3-liter reservoir will fit nicely into the hydration sleeve.
Answered by: REIservice
Date published: 2017-03-01

How easy is it to disconnect the hose and use the bag as water transport? I have an 80 L backpack and am planning a week long hike in the Grand Canyon with limited access to water. I will carry my 2L Platypus reservoir in addition to this one.

Asked by: Charlie
​The hose can be easily removed with the quick-release function so it can be used to simply transport water.
Answered by: REIservice
Date published: 2017-02-24

Will the Platypus Big Zip LP Reservoir - 3 Liter fit well in the sleeve of an Osprey - Atmos 65 AG?

Asked by: allenratta
The Platypus Big Zip LP Reservoir will fit well in the Osprey Atmos 65 AG.
Answered by: REIservice
Date published: 2015-09-20

I purchased the Big Zip about 2 or 3 years ago. Is this version BPA free? Thanks!

Asked by: EJ1234
The version you have is BPA free.
Answered by: REIservice
Date published: 2016-11-30
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