The backpack is made of waterproof 900D oxford, which iss Tear-proof, wear-resistant. This shoulder backpack measures 15 x 9.8 x 6 inch, 1 main pocket fits up to 2.5L water bladder, 2 front pockets for storing personal belongings tools, snacks, gadget, towel, phone, keys, 1 back pockets prevent valuable things from being stolen. Molle system can expand any extra gear which you like. Water backpack can adjust shoulder straps, chest straps and waistbands can make the backpack more suitable for your body shape. Comfortable shoulder padding, breathable light weight mesh covering alleviates any shoulder issues that may arise from long hiking, biking, walking, running, etc.