- Ultralight at 6.3 oz
- Air-Permeable Waterproof Breathable
- Fully Seam Taped
- 12d Micro Rip-Stop Nylon Shell
- Extremely Compressible
The Montbell Breeze Dry-Tec U.L. Bivy sack is the lightest waterproof breathable bivy on the market! It weighs only 6.3 ounces and stuffs down to the size of a pop can. Made from Air-permeable waterproof breathable 2-layer Montbell Breeze Dry-Tec™ fabric for superior breathability.
Keep yourself and your sleeping bag protected from moisture, dirt and the elements with this great ultralight bivy sack. Seams are fully taped to ensure waterproofness. Draw cord with cordlock allows you to quickly tighten the bivy sack around your face.
This 6 ounce wonder can be a life safer in cold and wet conditions! Use it in a tent in extreme wet weather, or as an emergency or minimalist shelter.
Regular: 6.3 ounces, Stuff Size: 3.5" x 2" x 7"
Max Dimensions: 88.6" x 33.1"
Long: 8.3 ounces, Stuff Size: 3.5" x 2.2" x 8.1"
Max Dimensions: 98.4" x 37"
Montbell has been making high quality outdoor gear since 1975. We see a lot of gear and we all agree that Montbell's quality is second to none.
Breeze Dry-Tec is an innovative new MontBell waterproof/breathable material, and one of the only air-permeable waterproof fabrics available today.


Waterproof/breathable materials generally consist of a micro-porous laminate with a non-porous polyurethane coating. This means that all vapors that will pass through the fabric must first be absorbed by and passed through the polyurethane coating and then through the micro-porous laminate and out of the jacket.
With Breeze Dry-Tec, MontBell was able to manipulate the size and consistency of the pores, eliminating the non-porous coating and drastically increase the ventilation of the material.
In fact, tests indicate that Breeze Dry-Tec is more than twice as breathable as many of its competitors while maintaining a high level of weatherproofing.