G4Free Big Sale Tactical Hydration Pack Backpacks for Hiking, Biking, Running, Walking and Climbing (Bladder Not Include) WATER RESISTANT - Made of upgraded high density and waterproof nylon, It is water resistant so your belongings stay dry in rainy days. It is also durable since it is wear and tear resistant. ABLE TO ACCOMMODATE 2.5L WATER BLADDER - There is a compartment in the main pocket design for putting Hydration Bladder. The bladder can be simply hooked on the hooks, keeping you hydrated for a day of hiking, cycling, running, biking, backpacking or camping, etc. (Hydration Bladder is Not Included.) PERFECTLY FIT - With adjustable shoulder and waist straps, it will fit your size perfectly, The waist straps make sure it doesn't bounce when you move. Approximate size: 16.1 x 9.05 x 3.93 inches. SUPER VERSATILE & MULTIFUNCTIONAL - There are 2 front pockets, 2 side pockets, and 2 drawstring pockest on the waist straps, which can store your phones, bottles and other gadgets. Multiple attachment and straps for hanging other items. BREATHABLE & COMFORTABLE - Breathable mesh back panel, thick and mesh shoulder straps make a breathable perspiration for this hydration backpack. The heat could quickly spread out, keeping you dry and cool after carrying it for a long time, and making your back feel super comfortable. Moreover, the thick shoulder straps relieve burden for your shoulder.