Marmot Men's Always Summer 40° Sleeping Bag

Marmot's Always Summer 40° is a warm-weather down mummy bag, manufacturer-rated to 8°C comfort and 3°C limit - marking it a two-season spring/summer bag rather than anything for shoulder-season cold. At 810 g it's light for a down bag, using 650-fill-power hydrophobic goose down that's RDS-certified, with DWR treatment on the shell for basic moisture resistance rather than serious wet-weather protection. The dual-side zipper is unusual for this range and, combined with a ventable footbox, is clearly built around regulating heat on warm nights rather than sealing it in - open one or both sides as it warms up, or zip up fully if a cool front moves through. A fitted, adjustable hood and draft tube along the zipper give some retention for cooler summer nights near the limit. It's cut men-specific, sized Regular for up to 182 cm, with one internal pocket and an included stuff sack. At roughly 270 g per degree of rated warmth, this bag is optimized for weight and ventilation over a narrow band - good for summer thru-hiking, not genuinely cold nights.