Compact, ultralight, stormproof bivy sacks, the Big Wall Hooped Bivy uses a sewn-in flexible wire, a dual-slider zipper that opens in the middle and a no-see-um mesh covered opening gives you some adjustable breathing space. It's built from waterproof, windproof and breathable ToddTex with a polyurethane-laminated floor. For security, the double storm flap and rain gutter use a seamless construction, and all other seams are factory taped. The Big Wall Hooped Bivy has all the features of the Hooped Bivy but incorporates an RF-welded tie-in point for total protection while you're clipped in.