Features a large main compartment with roll-top closure, protect your valuables from water and rain. A great choice for beach, boating, rafting, kayaking, swimming, surfing fishing, etc. Features: Made from super strong PVC material with precision welded seams, watertight and ultra-durable. Roll up design with quality buckle, safe and leakage proof. Feasures a single strap for 5L/10L/15L dry bags, two straps for 20L/30L waterproof backpack. Simple operation, just put your gear in bag, roll down tightly 2 to 3 times and then plug buckle to complete seal. Easy cleaning due to its large opening and smooth surface. Nice for hiking, swimming, boating, camping, cycling, mountaineering, hiking etc.