Big Agnes Greystone

With a 30°F temperature rating, this bag is designed for three-season use. It performs best in spring, summer, and autumn conditions, providing reliable warmth for most backpacking trips where temperatures don't dip significantly below freezing.

The 600 fill DownTek insulation is treated to be water-repellent, which helps the down retain its loft and insulating properties even if it gets slightly damp. While it's not waterproof, this treatment makes it much more resilient in humid environments than untreated down.

The Greystone features a traditional mummy cut, which is designed to maximize thermal efficiency by keeping the bag close to your body. If you are a restless sleeper who needs extra room for your legs or arms, you might find it slightly more confined than a rectangular bag.

The PFAS-free coating is applied to the exterior fabric to provide water resistance, causing light moisture or condensation to bead up and roll off the shell. It is a more environmentally conscious alternative to traditional chemical treatments without sacrificing the bag's ability to protect the insulation from dampness.

Big Agnes uses high-quality recycled fabrics for both the shell and lining, which are engineered to be just as durable and lightweight as virgin materials. You can expect the same level of tear resistance and longevity you would find in standard backpacking sleeping bags.