The dry bag is made by 500D PVC heavy duty waterproof backpack material, being flexible and durable. The backpack has been fully immersed waterproof test and the gear or clothing in the dry bag is totally dry and nice. You could trust this dry backpack during kayaking, canoeing, drifting, floating, camping, hiking and any other outdoor water sports. Independent on different occasions and personal hobbies, you can choose the moderate capacity backpack for your trip. If you do any water related things, this dry backpack would be a good choice. The 25 Liter dry bag is great for two to three days trip on the water. You just need roll the top of the dry bag 3-4 turns and clip buckles well,and reinforce the strip, which is simple and reliable.