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    MSR AC-Bivy

    The AC-Bivy from MSR is a super lightweight waterproof, breathable bivy that provides an all-condition refuge. Minimalists can have full-on, durable protection for a mere pound!

    • $199.95

    Item # 810038

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    • Top material uses a waterproof, breathable coating bonded to a tough yet lightweight ripstop nylon
    • Durashield™ polyurethane coating provides incredible waterproofness on the exceptionally durable nylon floor
    • Factory tape seam sealing provides absolute in waterproofness and out-of-the-store readiness
    • Envelope-style opening overlaps to provide a lightweight and simple entry; zippered mesh panel at the top end provides insect protection
    • 3D footbox provides ample room for campers with large feet, and comfort for everyone
    • Stash up to a medium-size pack in the hood area while you are inside; opening is situated to fit where your face is with the pack at the head for easy access
    • AC-Bivy fits you, your sleeping bag/pad and your pack!

    Please note: MSR products can only be shipped to U.S. addresses.


    Item 810038

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    MSR AC-Bivy Specs
    Best use
    3 - 4-season
    1 pound
    0.48 kilograms
    4 x 8 inches
    88 inches
    36 inches
    Sleeping capacity
    Weight - metric
    Packed size
    Bivy length
    Shoulder width
    Design type

    MSR AC-Bivy

    Loading Ratings & Reviews...

    Rated 3.7143/5 based on 7 reviews
    Rated 4out of5
    by fromIt's huge The other reviewers of this product seem to be above 6 feet and 240 pounds. If this one had a pole, I would feel like it was a one-person tent. I'm 5'5, 130lb. Even understanding that it's designed to have tons of room behind your head, I don't like the amount of fabric billowing over my face and bunching at my feet. It's incredibly lightweight and well made, despite all that. If you're a big guy you'll probably love it.
    Date published: 2013-05-08
    Rated 5out of5
    by fromvery well designed bivy This bivy is the best I have used yet. All other bivy's I have tried (6 different brands in the past 10 years) have all been either too narrow to allow reasonable movement while sleeping, or too claustrophobic, or too heavy, or all of the above. MSR got it right with this bivy. I am 6-1", weigh 240 lbs, and I have plenty of elbow room inside the bivy with it zipped up.... without feeling claustrophobic. The mosquito netting provides complete bug protection if needed in warmer weather. In cold weather the bivy adds about 10 degrees to your bags temp rating. I used this bivy recently on a 50 mile/four day hike in Los Padres National Forest in central CA (April 2011). We had rain, snow, freezing temps. I used the bivy with the Thermarest 35 deg alpine blanket and the MSR E Wing tarp shelter. I was toasty warm all night long, waking up to ice on the E wing tarp each morning. Very little condensation on the inside of the bivy. You just have to make sure you breath through the opening in the bivy, and not into the bivy itself. Very well designed, well thought out... I highly recommend it, and also recommend using the thermarest alpine blanket and the MSR Ewing tarp shelter.
    Date published: 2011-05-08
    Rated 5out of5
    by fromDoes what it says I opened mine new bivy on the trail (yea, I didn't check it before leaving...) so when I was setting up for the night, I realized that inside my AC-Bivy bag was not an AC Bivy but and E-Bivy someone swapped to get an AC-Bivy for half price. Well, the E-Bivy has no zipper or screen and it was raining. With a little improvising, I managed fine. Worked like a charm; the rain just rolled right off and this little brother even protected my junk sleeping bag. Keeps in heat too! I'll review the AC-Bivy when it comes; REI CS took my E-Bivy back and is shipping me what I paid for. Excellent product.
    Date published: 2011-09-17
    Rated 2out of5
    by fromGreat Bivy but... Just too hard to get into and out of quickly/easily (and to ventilate) with the 'envelope' design. If it had a side zipper I'd give it 5 stars. As is, I'm going to return it and get the REI brand with the zipper.
    Date published: 2012-01-11
    Rated 1out of5
    by fromAll in your face Used this camping on a 6 month trip. Having previously owned a MSR Advanced Bivy which I loved, I didn't realize how important the single pole was in keeping the bivy off your face and creating space. The design of the AC Bivy means that unless you tie it to an external point such as a tree, the material rests on your face. This leads to several other problems. Condensation is extreme, wind blows the bivy open, rain gets in easily, turning in your sleep shifts the opening, mosquitoes can bite you through the mesh as it rests on your face... The only practical use I found for the AC Bivy was keeping a down bag dry when sleeping inside a tent.
    Date published: 2013-10-25
    Rated 4out of5
    by fromSolid shelter I bought the MSR AC Bivy for my hike of over 1000 miles on the Pacific Crest Trail this year. This bivy was my shelter nearly every night for over 3 months, and I never got tired of it. I particularly enjoy laying out under the stars, yet being sheltered inside the bivy from the elements and insects. The envelop design with a mesh panel allows for celestial views, and makes it easy enough to slip in and out of. A tarp also accompanied me in case I had to weather any serious precipitation, and I would carry one in addition to the bivy on future hikes. However, I hardly used the tarp on the PCT as most often the bivy was sufficient shelter. I find the bivy adds several degrees of warmth to my sleep system, and often cut the chill from wind. In high winds, though, the bivy helps little and often the hood billows up when it catches a strong gust. A loop on the lip of the hood allows it to be guyed out, potentially reducing billowing. The MSR AC Bivy is an efficient shelter and I recommend it to any backpacker looking to shed some weight from their pack. I will be taking this bivy as my shelter on future hikes, including a thru-hike of the Appalachian Trail next season.
    Date published: 2013-08-21
    Rated 5out of5
    by fromGet the tarp too I took this bivy with me to Yosemite for a 5 day hike. With rain in the forecast, I also bought the MSR Tarp (a little spendy) but as a pair, they're a ultra-lite match for dryness. The tarp kept 99% of the rain at bay and the remaining had no effect on my Mountain Hardware Phantom 15 sitting roomy and cozy in the bivy along with my High Sierra Phantom 45+10 at my head (also covered and dry). Condensation as expected (mostly at the feet), but dried right up in the morning sun in about 15 minutes. Love this pair (bivy + tarp).
    Date published: 2011-11-01

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