The Nemo men's Kayu ultralight down mummy bag, with packable 800FP down and aggressive, thermally-efficient patterning, is the Nemo's pinnacle bag for ultralight adventures. With careful attention to tailoring of each curve for efficiency and comfort, the contoured hood, shaped footbox, and body-mapped tapered core are designed for ideal fit with no excess or wasted space. The Nemo men's Kayu ultralight down mummy bag, with packable 800FP down and aggressive, thermally-efficient patterning, is the Nemo's pinnacle bag for ultralight adventures. With careful attention to tailoring of each curve for efficiency and comfort, the contoured hood, shaped footbox, and body-mapped tapered core are designed for ideal fit with no excess or wasted space. Premium 800 FP down is hydrophobic, PFC-free, and 100% Responsible Down Standard A fabric set of 20D Nylon Ripstop and 30D Nylon Taffeta is ultra-plush for a supreme sleep experience Thermo Gills allow you to vent body heat without letting cold drafts in Premium down insulation is treated with Nikwax for waterproof security on the trail