Big Agnes Sidewinder SL 35 (650 DownTek) Regular

Many of us change positions during the night or sleep on our sides and traditional sleeping bags don't always cooperate with nocturnal movement. The water-resistant down-insulated Big Agnes Sidewinder SL 35 Degree mummy-style bag provides warm-weather backpacking performance while adjusting as you roll around during the night to ensure consistent, reliable performance.

The bag is insulated with 650-fill DownTek hydrophobic down. Down insulation has long been renowned for its compressible properties and efficiency in delivering an excellent warmth-to-weight ratio. The shortcoming of down has been its susceptibility to the effects of moisture, losing much of its performance qualities when wet or damp. DownTek insulation utilizes nano technology and a proprietary application process to provide water-repellency and both anti-microbial and anti-bacterial protection. Using body-mapping for key areas of vulnerability to moisture, Big Agnes applied post-consumer recycled FireLine ECO synthetic insulation to bolster weather protection. A nylon ripstop shell with a DWR finish further protects against the elements while a polyester taffeta lining enhances comfort.

The bag's technical and strategic patterning allows the bag to flex with you if and as you turn and move. While doing so it continues to eliminate "dead" space within the bag that could otherwise create cold spots but never feels restrictive. A jacket-style insulated hood with an internal insulated baffle delivers warmth regardless of your sleeping position. A uniquely designed "pillow barn" comfortably situates a backpacking/camping pillow (pillow sold separately) beneath your head whether you are lying on your back, your right side, or your left side. An insulated draft tube behind the bag's anti-snag zipper keeps cold air out of the interior of the bag.