Big Agnes Star Fire

The 20°F rating is a comfort-limit standard, meaning it is designed to keep an average sleeper warm down to that temperature. If you are a cold sleeper, we recommend pairing it with a high-R-value sleeping pad to ensure you don't lose heat through the ground.

The 850 fill power DownTek treatment helps the down clusters resist moisture and retain their loft even if they get slightly damp. While it is not waterproof, it performs significantly better than untreated down in humid or misty environments.

This design places insulation exactly where you need it most, optimizing warmth-to-weight ratio by preventing down from shifting away from your core. It allows the bag to be lighter and more packable without sacrificing thermal efficiency.

The Star Fire UL uses an ergonomic design that balances a snug, heat-trapping fit with enough room to move. While it is a traditional mummy shape, the contoured hood and footbox are built to accommodate natural sleeping positions rather than feeling overly tight.

The Pertex shell is chosen specifically for its high tear strength-to-weight ratio. It is tough enough for backcountry use, though like all ultralight gear, it should be kept away from sharp objects like crampons or stove edges.

Yes, the bag features a 3-D anti-snag draft tube designed to prevent the fabric from catching in the zipper track. It is a reliable system that makes getting in and out of the bag much smoother, especially in the dark.