Mountain Hardwear Phantom™ 15F/-9C

The Mountain Hardwear Phantom 15F/-9C sits between the brand's 3-season and 4-season Phantom bags, rated 3-4 season and built with 800-fill goose down (550 g fill), hydrophobic-treated, inside a 10D recycled nylon Ghost Ripstop shell with a 15D nylon ripstop liner. Down is arranged in horizontal box baffles for consistent loft, and this particular model is not RDS-certified, unlike several other bags in the Phantom line — worth noting if third-party down sourcing certification matters to you. EN/ISO 23537 testing puts comfort at -3°C, limit at -9°C, and extreme at -28°C, with a total weight of 941 g and a packed volume of 4.9 liters — solidly ultralight for a bag rated into shoulder-season cold. This is the men's-specific, short-length cut, sized for users up to 172 cm, so taller hikers should look at the regular-length Phantom instead. Full-length two-way zipper, draft collar, and draft tube round out the weather sealing. It suits high-alpine traverses and multi-week backpacking trips where warmth-per-gram matters, provided the shorter length and men's fit match the user.