What Our Gearhead(R) Experts Are Saying: "This is my go-to for late spring through early fall. It's shockingly small in the pack and still cozy when temps flirt with freezing."We keep pace with the Sea to Summit Spark 30F. Light, compressible down and efficient baffles deliver just-right warmth for alpine meadows, desert rims, and shoulder-season ridgelines. It packs smaller than a water bottle and is easy to live with from trailhead to summit.