The Helium Bivy is our lightest, best-selling, and most awarded bivy sack. Thru-hikers and bikepackers love the Helium for its refined footprint and reduced weight and trust it for its durable, lightweight, waterproof Pertex® Diamond Fuse technology. Incredibly quick to set up and break down, the ultralight Helium Bivy is 14% lighter than its last generation and has everything the outdoor minimalist needs to be comfortable. A clamshell opening makes it easy to get in and out and resists wear and tear for future seasons of adventuring. The ideal shelter for minimalists looking to trade weight for speed, agility, and performance, the Helium Bivy is a fast-and-light essential.