Western Mountaineering Versalite

The Versalite sits at the cold end of Western Mountaineering's ExtremeLite series, rated to 10°F (-12°C) with 850+ fill-power goose down and a differential cut that keeps down loft evenly distributed around the body. At 905 g (Regular) with 565 g of fill, it posts the highest warmth-to-weight ratio of the brand's bags covered here — a sign of how efficiently the continuous-baffle, differential-cut construction converts fill into usable warmth. Cold-weather details back up the rating: a fully insulated draft collar and draft tube seal out drafts at the neck and zipper, and an adjustable, fitted hood traps heat around the head. Unlike some lighter bags in the range, the Versalite ships without a stuff sack, though a storage sack for long-term loft is included. The shell carries no water-resistant treatment, so it depends on a dry sleep setup or an outer bivy in wet conditions. This is a shoulder-season-into-winter bag for hikers prioritizing warmth per gram over all-around weather protection — ExtremeLite territory rather than a general three-season pick.