2.5 Liter Dry Bag is made of 210T 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!