![NEMO Sonic -20 (2022) One Color](http://mtnchalet.com/cdn/shop/products/92-1098964-0-image-1528113_640x640.jpg?v=1645098582)
Built to be the only bag you need from -20 F to 40 F, we've updated our Backpacker Editors' Choice award-winning big-mountain bag, Sonic, for even greater warmth, tuneability, and reduced environmental impact. With this bag, we are launching our next-generation Thermo Gills with a new multistage zipper system that dramatically increases the usable temperature range of the bag and allows fine-tuning of comfort from within the bag.