The SealLine Blocker PurgeAir Dry Sack is a fully waterproof roll-top stuff sack with air vent, for organizing and packing essential clothing and gear in backpacks and duffels, for trail and paddling adventures. Waterproof construction with a roll-top closure features a wrinkle-free stiffening strip to ensure that sack contents are kept safe and dry. A PurgeAir valve vents trapped air, helping the sack to compress further after being sealed, maximizing space in a pack or bag. Fully welded seams provide unmatched strength and durability, compared to sewn-and-taped seams, and the 70-denier polyurethane-coated nylon is tough and versatile for reliable all-around waterproof protection. Unlike traditional, rounded stuff sacks, the SealLine Blocker PurgeAir Dry Sack is shaped like a rectangle with flat sides that nestle closely together and pack 20 percent more efficiently, for space-saving organization. Available in a variety of sizes and colors for building out the perfect packing system for backpacking, camping, boating, expeditions, and travel. Manufacturer's limited lifetime warranty. Made in the USA.