This backpack is designed for 2-3 night travel or for touring and diving expeditions. DRY TANK is a basic model of stream trails, boasting outstanding waterproof performance. The surface material used in waterproof bags is made of polyester fibers that are welded together with synthetic resin film. It is also used in banners such as tents and outdoor advertising banners often found in towns, and construction sites. It is resistant to water and tear and resistant to abrasion. The opening is easy to fill with water, and the waterproof flap is rolled down to provide outstanding waterproof performance and a soft fabric that is easy to roll. It can be easily wiped off with some dirt, making it easy to care for, so you can use it on the field or on the town. Even if you store wet items, the water accumulated inside can be discharged from the drain plug. DRY TANK 40L Camouflage pattern comes in two colors. The classic GREEN camouflage is not too dark or too strong and is a calm earth color SAND that blends with nature. The DRY TANK series is perfect for a variety of occasions, from professional outdoor activities to daily use. There are 4 types of inner pockets that can be attached and detached with Velcro tape for storage of small items. Also available in all DRY TANK series drink holders and mobile holders for external use. Inner holder sold separately. Roll-down flap opening with waterproof flap on opening to prevent water from entering Roll down for a high level of waterproofing It is effective when it comes to rain. In addition, the contents will not pop out when the bag is knocked over. Tarpaulin fabric is hardened when temperature drops, so we use a nylon fabric that won't harden even at low temperatures on the flaps where flexibility is required at all times.