Built to be the only bag you need in colder weather, the award-winning Nemo Sonic 0 down sleeping bag has great warmth, tuneability, and a reduced environmental impact. Adaptable to whatever the mountain throws at it, Sonic reverberates as the ultimate extreme weather companion. Premium 800 FP hydrophobic down is 100% Responsible Down Standard (Rds) certified Next-generation Thermo Gills with a multistage zipper allow fine-tuning of your comfort range Chevron baffles compartmentalize the down for more uniform loft and down migration prevention Updated profile secures warmth closer to the body Stretch construction at the knees for comfortable side sleeping Toester waterproof/breathable footbox keeps feet warmer and protects down from moisture Draft collar and draft tubes keep cold air out Offset zipper creates a thermally efficient seal The shell and liner fabrics are 100% recycled and bluesign approved Compression stuff sack included Manufacturer lifetime warranty against defects in materials and workmanship