Zipper access on the Zip Sacks makes it easy to grab a fresh pair of socks or a warm hat without unloading your entire pack in the middle of the trail. Technical specs Best Use Backpacking Gear Capacity (L) S: 4 liters M: 7 liters Gear Capacity (cu. in.) S: 244 cubic inches M: 427 cubic inches Closure Zippered Material(s) Polyester/nylon with polyurethane coating Dimensions S: 8.25 x 6.38 x 3 inches M: 10.25 x 7.75 x 4 inches Weight S: 1.1 ounces M: 1.4 ounces Features Polyurethane-coated polyester and nylon stand up to frequent use, and water-repellent base and water-resistant zippers help fend off moisture Well designed to the last detail, the Outdoor Research Zip Sack includes webbing handles on the ends for leverage when opening zippers