Ascent series bags are the most versatile in the Sea to Summit lineup. They combine very low weight with comfort and functional detail. - "Relaxed mummy fit" for great thermal performance without being too narrow for comfort - RDS certified and Ultra Dry treated duck down fill doesn't lose loft as dramatically as untreated down - Free Flow zipper system: long zipper on the left, short on the right - Thermal collar - The hood has room for the manufacturer's Regular size hiking pillows - The bag can be combined with women's Sea to Summit sleeping bags with its zipper - The bag can also be combined with Sea to Summit quilts for extra warmth -