Sea to Summit Ascent Sleeping Bag

The Free Flow Zip System features a three-zipper configuration that allows you to open the bag in different ways. You can unzip the foot box for ventilation, open the top like a quilt, or use the half-zip on the opposite side to fold down the top edge, giving you precise control over your temperature without leaving the bag.

The Ascent is rated for 15 degrees Fahrenheit, making it a solid choice for three-season use. While it can handle late autumn or early spring frost, it is not designed for deep winter expeditions where temperatures consistently drop below that rating.

A standard mummy bag is cut close to the body to maximize thermal efficiency, which can feel restrictive. The relaxed mummy fit offers extra room in the shoulders and hips, allowing you to move more freely or sleep on your side without feeling constricted.

Yes, the Ascent is designed to be compatible with other Sea to Summit bags. You can zip two compatible bags together to create a double sleeping system, provided you have one left-zip and one right-zip model.

Yes, the bag uses box baffle construction. This internal structure creates individual chambers that keep the 750+ fill power down evenly distributed, preventing cold spots caused by the insulation shifting or clumping.

The shell is made from durable recycled nylon with a DWR (durable water repellent) finish, which makes it water-resistant, not waterproof. It will shed light moisture and condensation effectively, but it should not be submerged or used in heavy, sustained rain without a tent or bivy.