The 20.0 Liter Dry Bag is made of 190T Ripstop Polyester with PVC backing . It has a clear inside pocket for handy storage of a cell phone (which can be operated through the clear window) . The Roll Top and Buckle Closure ensures your valuables are safe and dry inside the bag . Perfect for food, snacks, spare clothes and valuables when outside for a day on the hiking trail or at the beach, lake or other outdoor destinations . The Buckle Closure is also a carrying handle or clip it onto other bags, a backpack or even a belt loop . For proper use, fold top of bag down 3 times before snapping buckle together!