• Online:
  • URL for this product:
  • From the U.S. and CanadaCall 1-800-426-4840
  • Mon. through Sun., 4 a.m. through 11 p.m. PT.
  • InternationalCall 1-253-891-2500
  • Mon. through Sun., 4 a.m. through 11 p.m. PT. English language only.

Osprey Manta 20 Hydration Pack - 100 fl. oz.

This item is currently sold out or unavailable online.

Or, may we suggest shopping for similar items:

Shop more Hydration PacksShop more Osprey

This page is provided for reference to historical product information.

The Osprey Manta 20 hydration pack combines great carrying comfort with the latest in easy, functional hydration, all in a streamlined design that lets you focus on your adventure, not your gear.

  • Osprey Hydraulics™ system features a reservoir that sandwiches an anatomically shaped plastic sheet between a layer of nylon fabric and the reservoir back
  • Design conforms the reservoir to the back's shape even when full, resulting in a precise, stable and comfortable fit
  • Reservoir features a rigid spine/handle that stabilizes the water load and makes it easy to slide the reservoir into the pack
  • Rigid spine/handle and large mouth make filling and cleaning the reservoir a snap
  • BPA- and PVC-free reservoir does not retain tastes or odors and features AquaGuard™ antimicrobial formula to help prevent bacteria and mold
  • 180° pivoting on/off valve rotates in either direction for quick and easy flow control; magnetic sternum-strap buckle secures the bite valve when not in use
  • AirSpeed™ suspension incorporates a lightweight alloy frame and cross struts with a tensioned mesh back panel for support and flexibility
  • Breathable mesh and perforated, molded waffle foam at contact points on contoured shoulder straps and hipbelt enhance breathability and comfort
  • Panel-loading main compartment is spacious enough for your done-in-a-day food, clothing and gear
  • Zippered front organizational pocket with key clip holds small items; zippered top pocket with soft lining helps keep sunglasses or other fragile items from getting scratched
  • Stretch-woven front pocket offers quick external storage and access; integrated patch holds a blinker light (sold separately)
  • Zippered pocket on hipbelt keeps small essentials within easy reach
  • The Osprey Manta 20 hydration pack features an integrated raincover that can be deployed quickly to keep contents dry


Item 796750


This item's hot - and it's only available online.

REI Membership

Osprey Manta 20 Hydration Pack - 100 fl. oz. Specs
Best use
17 / 20 liter
1,000 / 1,200 cubic inches
3 liter
100 fluid ounces
2 lbs. 9 oz. / 2 lbs. 12 oz.
1.16 / 1.25 kilograms
<19 / 19+ inches
<33 / 33+ inches
Metal alloy peripheral hoop/EVA back panel
4 + main compartment
18.5 x 9.5 x 8.5 inches
Frame type
Gear capacity (L)
Gear capacity (cu. in.)
Liquid capacity (L)
Liquid capacity (fl. oz.)
Weight - metric
Adjustable torso
Fits torso
Fits waist/hips
Frame material
Pack loading
Number of exterior pockets
Bite valve shut-off switch
Quick disconnect tubing
Wide-mouth opening

Osprey Manta 20 Hydration Pack - 100 fl. oz.

Loading Ratings & Reviews...

Osprey Manta 20 Hydration Pack - 100 fl. rated4.3333out of5by3.
Rated5out of5byfromGreat packThis is my second Osprey pack. I bought the first one years ago, the one was much big than this one and was great for hiking. I love this pack, the size is smaller and great for biking,trail running and summy day hike, great quality. I love it.
Date published: 2013-02-27
Rated5out of5byfromGreat product!I just bought the Manta 20 in the beginning of January. Got to test it out in February. I went up to Sequoia National park for a few days. This backpack is amazing! I had no problems with it whatsoever. I read a lot of reviews complaining about a leaking bladder, mine is great so far, and the bite action valve does not leak either. I love the little magnet on the chest strap for the bite action valve, make things much easier. The whole hydration system works great and I love it, my first pack with a bladder. This is the most comfortable back pack I've ever owned, if strapped properly you don't feel any wait on your shoulders or back at all. I hiked for several hours for 3 days and packed it to capacity including a full bladder. It's definitely a day pack though, a lot of little pockets you can fill up with little things, like snacks ,gadgets etc but the main compartment is kind of small because the bladder goes right behind it, I put my midlayer jacket there, a beanie and gloves in it was almost full, could probably squeeze in a bit more. Overall I'm very happy with the quality comfort and pretty much everything, can't say anything bad about this pack, oh almost forgot to mention the integrated rain cover that is stored on the bottom of the pack in a zipped compartment, just unzip and pull it over the pack.
Date published: 2013-02-20
Rated3out of5byfromGood and badI'll start of by saying this is the most comfortable daypack I've ever owned-- hands down! The hydration system is also great-- that little magnet is genius. The frame is also extremely stable. I love it. My issues are mainly its durability and size. At the store, the size is misleading. Even with the flatter hydration system, it does take up a lot of room. I typically have to squeeze in what I need to bring for a long day-hike but it's doable. Also, the outside is beginning to wear through. I'm going to have to patch it soon. I will always buy Osprey packs because of their comfort and stability, but next time I will buy one a little bigger and sturdier. I'm in the desert and often hike off-trail. I need something tougher.
Date published: 2012-11-19

Ask a question and have it answered by REI product experts and fellow outdoor enthusiasts. Need immediate assistance? Use Live Help.

Loading Questions & Answers...

How are we doing? Give us feedback on this page.

FREE SHIPPING With $50 minimum purchase

MEMBERS, EARN A $20 BONUS CARD! When you spend $100 April 14-29. Single-use bonus card redeemable May 2-12. Details
  • Join REI today!
  • REI Membership
  • REI member benefits include an annual refund (typically 10% on eligible purchases).
  • Join REI today!
  • Sign up for REI Gearmail®
  • and get 15% off selected items!
  • Store Locator
  • Locate an REI store near you.
  • Find a Store
© 2014 Recreational Equipment, Inc. All rights reserved. REI, the REI Tree and Mountain design, Novara, and
REI Adventures are trademarks of Recreational Equipment, Inc.

Find REI on: FacebookTwitterYouTubeFlickrMobile site