Throw it in the boat or truck bed–your gear will be dry when you get there. The Filson Dry Small Bag is fully waterproof, with a dependable roll-top closure. Built with tough 840-denier nylon tarpaulin fabric coated with thermoplastic polyurethane (TPU), water simply cannot penetrate it. This coated nylon fabric is lightweight, flexible and abrasion-resistant. The TPU coating is resistant to ultraviolet light and chemicals, ensuring durability and longevity without breakdown from hard use. The seams are radio-frequency (RF) welded, a cement-free process that permanently fuses the fabric layers together, assuring lasting flexibility and integrity. This is the same construction as used in the manufacture of white-water rafting gear. With the top rolled down three turns and snugly buckled with the side-cinch straps, water cannot enter the bag. This closure design also affords the ability to compress the bag for varying load sizes. This compact dry bag works well on its own for keeping gear organized and dry or as added protection for gear that must remain dry inside of a backpack or duffle.