"Less is more" doesn&';t always ring true, but the Alpine AscentShell Bivy packs as much as possible into a small alpine shelter. On our lightest ascents into the wilderness, this bivy offers serious protection in all four seasons. Outdoor Research&';s Helium AscentShell membrane keeps us secure in unruly weather, and it boasts breathability that ensures our outdoor comfort during the hotter months as well. Details:- Four-season bivy for alpinism and solo backcountry adventures Helium AscentShell floor and fly keep rain, wind, and snow at bay Mesh screen allows more airflow on hot summer nights Large, step-in opening offers easier, more comfortable entry Single pole design makes setup fast Packed only weight barely exceeds one pound High volume toe box and extra headroom for gear storage and roomy comfort