The Blocker compression dry bag saves space while paddling or on a trail, while the waterproof valve rapidly vents trapped air to ease compression. It is full waterproof ensuring your essential contents are protected. Made out of lightweight 70D polyurethan-coated nylone for a tough resilient bag. The continuous compression system on this bag encircle the sack to minimize seam strain. The PurgeAirTM valve vents trapped air, helping the sack compress further after it is sealed. The Roll top closure features a wrinkle-free stiffening strip to ensure a secure seal. Weight: 6.9 oz 6.2″ x 12″ x 22.8″ Volume: 30 liters 70D polyurethane-coated nylon