Traveling light demands sacrifice, but you don't need to sacrifice storm protection when you have the MSR AC-Bivy. This waterproof bivy sack is designed to handle storm conditions and keep you comfortable. The waterproof ripstop nylon material is highly breathable and is matched to a Durashield-coated floor for maximum protection and durability. A zippered mesh closure around the head adds ventilation and all-important protection from bugs. This lightweight one person shelter also adds valuable warmth to your sleeping bag, literally extending your bag's comfort range. You get all of this for a mere pound. That's right; the AC Bivy weighs in at one pound, making it a great match for minimalist hikers and solo bike touring. Combine this bivy sack with a versatile tarp shelter and you've got everything you need for sleeping, cooking and chilling, regardless of the weather. It's so light and compact it can even be packed as emergency shelter. Make your next adventure as light as possible with the MSR AC Bivy.