Nanfeng Hydration waterproof pack for Running Hiking Riding Hiking Camping Cycling Climbling Biking - Lightweight Backpack,Blue Not Include Water Bladder! Nylon material, water and sweat resistant, anti-scratch, durable. Double-layer design, special inner layer for holding water bladder. Including a water tube retainer clip for holding drinking tube. Adjustable chest and shoulder wide straps, thickening and soften back design. Net for holding the helmet Large capacity of more than 7 liters, more than a hydration backpack, enough space for 13" laptop. Carry more things when you hike or ride. Two side pockets for even more space. Airflow system design, keep your back cool and dry.