The bag is insulated with premium 850-fill DownTek insulation. 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. A nylon mini ripstop shell with a DWR finish further protects against the elements while providing lightweight durability. A polyester taffeta lining helps to manage moisture and enhance comfort.

Body-mapped baffles help to effectively eliminate cold spots and reduce weight. Zippered side panels that run from the shoulders to the foot of the bag allow you expand the overall girth of the bag by 10” (5” per side) so you can choose between maximum thermal efficiency or extra room to sprawl. Other features include an insulated and contoured hood, an ergonomic footbox, a mesh interior stash pocket, an interior draft collar, and a draft tube that runs the length of the 70" zipper to lock in heat and keep out cold air.