Remarkably light and compact, the Helium 15° Sleeping Bag delivers impressive insulation during three-season backpacking and mountaineering treks. Featuring Pertex® Microlight on the exterior, its lofty 800-fill-power-down insulation and water-resistant Down Defender treatment will keep you warm and dry. After an epic day on the mountain, give your feet a rest in the roomy wrap-around footbox. Smooth, curved baffles help keep the fill in place, while the nautilus multi-baffle hood with a drawcord, snagless insulated draft tube, and full-length, two-way zipper with a zip-guard slider limit heat loss. If the interior gets too warm, use the fold-down secondary zipper to get some air. Tuck small items into the internal stash pocket.