The Unigear waterproof bag is made of stiff 500D PVC material and designed with a roll-top closure to protect your belongings from water, sand, dust, and dirt. It features fully welded seams by high-frequency tech, providing a stronger and more durably waterproof construction. The dry sack is abrasion-resistant and perfect for outdoor activities like boating, fishing, paddling, swimming, and hiking. It comes in different sizes from 2L to 40L, with a single strap for 2L/5L/10L/20L dry bags, two straps for 30L and 40L waterproof backpack. The buckle and D-rings are upgraded with POM material, making it stronger and more durable.