Vapr NANO Bivy Sack (Pertex Quantum)

Weighed On Our Scales » 4.6 oz

Vapr NANO Bivy Sack (Pertex Quantum)

NANO bottom, Pertex Quantum top, 4.6 ounces!

25% Lighter than Vapr Bivies

Colors: Vapr NANO Bivies vary in colors and cannot be specified: each production lot uses what stock of Pertex Quantum is available to us for the uppers: light or dark gray, navy blue, or black) and translucent white for the floors.

Overview of the Vapr NANO Bivy Sack

The Vapr NANO Bivy Sack is now the lightest full-featured bivy sack on the market: 4.6 oz for the bivy body in Size R.

The new NANO bivy retains the breathability of Pertex Quantum for its upper, but is manufactured with an exceptionally light fiber-reinforced polyester film floor that offers a tear strength that is about 10 times the amount of a similar weight woven nylon.

Primary application: All of our Vapr bivies made with Pertex Quantum uppers are intended for tarp campers, winter hiking enthusiasts, and others who value the ability to keep their sleeping bag dry and protected from rain spray, condensation dripping, and spind drift. These bivies are designed to be used in conjunction with another overhead shelter (or as a standalone shelter in sub-zero, very dry conditions, or dry desert environments).

Special Notes About the NANO Bivy: The NANO version of the Vapr Bivy is an extremely specialized product. First of all, it's a full-sized bivy sack that does not skimp on interior volume to save weight. There is plenty of room for a winter sleeping bag to loft, and plenty of storage area in the hood for gear, shoes, spare clothing, etc. With an empty pack under your lower legs, all of your gear (assuming you "pack light"!) should easily fit into this bivy sack.

Limitations of the NANO Bivy: The NANO bivy is manufactured with a fiber-reinforced manufactured polyester film floor. As such, although the tear resistance of this material is very strong (about 10 times the tear resistance of a similar weight nylon), it is not as puncture resistant as bivy sacks made with tightly woven, coated (urethane or silicone) nylons. While urethane-coated nylons offer good puncture resistance due to the thickness of the coating, and silicone-coated nylons offer good puncture resistance by self-sealing the holes, NANO bivy floor fabric offers puncture resistance only as a result of the resilience of the film. Consequently, we do NOT recommend using the NANO bivy if you (1) absolutely have to have total and serious water resistance because you are camping in very wet locations, and you (2) are camping on ground where sharp objects are likely to puncture the bivy sack. If you are wondering about if the puncture resistance for this bivy is "adequate for your needs", and you are sitting on the fence, then you probably aren't ready for this bivy.

Need To Make This Bivy Sack Lighter?

By Ryan Jordan

My Nano Bivy is 3.6 ounces.

To get there, I completely ditched the zipper. Cut the entire zipper tape out carefully, then fell a drawcord tube into cut line and hem it shut. Cut the zipper flap off. Use AirCore 1 for an ultralight drawcord and a tiny cordlock.

Wear a headnet for bug protection, if you carry one anyways. If you only want the bug protection at night, and noseeums aren't a worry, then buy some Tulle mesh at JoAnn Fabrics and sew a flap of mesh along the top of the bivy opening. Just fold it back and out of the way when you don't need it. Otherwise, fold it forward to cover the bivy opening.

Trim the stake loops, too, and sew the bivy to a tighter size if you don't need all the space, then cut out the extra fabric.

Yeah, these are sort of hard core mods. But that's the idea, you know?!

Related Info

The Vapr NANO Bivy is a lighter daughter of the Vapr Bivy.



  • Breathable DWR-coated ripstop-nylon top.
  • Fiber-reinforced polyester film bathtub floor is waterproof in 99% of the wet conditions we've faced.  Wetter conditions would be more comfy by sealing the floor seam.
  • Four grosgrain ribbon stake-out loops at corners to keep bivy in place during the night
  • Contoured footbox and box bivy body to prevent compression of sleeping bag loft, even for winter bags
  • Cross-chest traditional bivy opening (zippered) to save weight
  • Large hood provides plenty of room for gear storage, pillow, etc. Some of our customers even purchase the long size bivy and store their ultralight packs in the hood
  • Grosgrain loop at top of hood can be tied (e.g., to the peak of your tarp), providing extra headroom while in the bivy to prevent that non-lovin' claustrophobic feelin', and heck, you can even read inside - more room than you think! Also improves ventilation significantly.
  • Zip-out noseeum mesh window can be left in for buggy conditions, zipped fully open for maximum ventilation, or simply left at home to save weight. With the window zipped out, the chest zipper of the bivy still zips shut for maximum storm protection and warmth. This versatility is accomplished through no slight magic of technological zipper wizardry.


  • Lengths:
    • Regular: fits sleeping bags up to 6’0”
    • Long: fits sleeping bags up to 6’6”
  • Weights: 
    • Regular: 4.6 oz (130 g)
    • Long: 5.3 oz (150 g)
    • Netting Window: 0.9 oz (26 g)
    • Stuff Sack: 0.2 oz (6 g)
  • Max Girth: 76 in (193 cm)
  • Colors:  Vary based on fabric availability, but muted
Size: (Will update display)


Regular Price$269.99
Member Price$256.49
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