Outdoor Research Zip Sack Hardshell accommodates a wide range of

accommodates a wide range of head sizes

rock-solid DynaLock™ adjustability with tool-free tensioning

dry or wet

Compressed air is sold separately

Outdoor Research Zip Sack Hardshell accommodates a wide range ofZipper 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