BOLANG Outdoor Hiking Pack Internal Frame Backpacks Camping Climbing Bag 8145 nylon Importado Powerful Aircomfort system, breathable perspiration, relieve burdened Powerful Bear Breathable System, the heat could quickly spread out, avoiding the embarrassment of sweat, also it's more comfortable for your back Large Front Stretch Stuff-it Pocket,1 front pocket, a main pocket,A bottom rain cover pocket, 2 Hipbelt Pockets cell phone/MP3 player there is a compartment in the main pocket design for putting Hydration bladder Capacity: 40L Size: 20"x12"x6" ;Capacity: 55+5L size:25"x12"x8"