Sea to Summit Altitude Sleeping Bag

The Altitude Ati is rated for 25 degrees Fahrenheit, making it a solid choice for late autumn or early spring backpacking. If you are camping in temperatures consistently below freezing, you may want to pair it with a high-R-value sleeping pad or a liner to ensure you stay comfortable.

The Free-Flow system features a full-length main zipper, a half-length zipper on the opposite side, and a footbox zipper. This allows you to vent just your feet, open the top for airflow, or even open the bag completely like a quilt if the temperature rises unexpectedly.

This bag uses ULTRA-DRY Down, which is treated to resist moisture. While it is not waterproof, the treatment helps the down maintain its loft and thermal efficiency much better than untreated down when exposed to condensation or humid alpine air.

The maximum user height for this bag is 67 inches, or 5'7". At 5'6", you will fit, but it will be a snug, performance-oriented fit. If you prefer extra room to move or want to store gear inside the bag, you might find it a bit restrictive.

This bag is cut slightly wider at the hips and narrower at the shoulders compared to standard unisex bags. This shape is designed to reduce dead air space, which helps you heat the bag up faster and stay warmer throughout the night.

Yes, it includes a lightweight compression bag. It is designed to pack the sleeping bag down to a manageable size for your pack, though you should store the bag uncompressed in a larger storage sack at home to maintain the down's loft over time.