Nylon Sierra Designs has made high performance backcountry camping gear and outdoor clothing - from ultralight tents, sleeping bags and jackets. Our products are all specifically designed to make getting outside, easier and more enjoyable. All Sierra design products are made with high-quality breathable top fabric which provides increased comfort. A lightweight mummy with some tricks up its sleeve, the Nitro brings the classic mummy shape back at an impressively low weight, with incredible comfort. Thanks to the Nitro’s 800 Fill Power of responsibly sourced and traceable DriDown from Allied Feather + Down as well as the DWR-treated nylon shell, you can say goodbye to cold spots. With a simple construction and lightweight materials, the Nitro comes in punching above its weight class, and still features our self sealing foot vent for comfort.