Streamlined Compact Design: 47 x 20 x 10CM in size. Ergonomically fits f your shoulders, chest, waist. 3 straps are all adjustable f reducing bounce. Soft air mesh back speeds up air-flow makes your back cool. Foam padded shoulder straps are extremely comftable. Practical Functions: 1 main pocket fits up to 3L water reservoir with either large small opening. 2 external pockets f sting personal belongings wallet, gadget, towel, phone, keys. The MOLLE system allows you to carry me items. Professional 3L Hydration Bladder: Quick release valve allows you to refill water without connecting hose. Large opening is easy to clean add ice cube. 360 degrees rotatable mouthpiece allows f easy drinking. Shut On or Off valve helps to adjust water flow. Middle baffle keeps the bladder flat makes it easier to place into the backpack. Versatility: Frees your hs while drinking, this hydration pack is your perfect choice f sht trip, camping, bike riding, walking, mountaineering, kayaking, skiing, snowboarding. A decent Holiday Gift f families friends who love outdo spts. Col: black and green Material: Oxfd clothandEVA Cleaning: Befe the first use, fill the bladder with dish soap baking soda warm water, run the liquid through the tube mouthpiece, then let them sit f 2 hours. Rinse them all several times with clean water let them air dry. Stage: Empty the water, rinse clean make sure it is completely dry befe sting. Main pocket can hold either large small opening water bladder, compatible with most of bladders on the market. Two external pockets are used to place personal items -shirt, toiletries etc. The MOLLE suspension system exps to attach me items. Shoulder, chest waist straps can all be adjusted to your comftable size, keep the pack snug to your back. Three breathable mesh pads at the backside make rapid air flow, while even the weight to your back f ultra relaxed carrying. Well-designed Leak Proof 3L Hydration Reservoir Quick Release Valve: No longer need to hold the long hose to fill water, just detach the hose to fill water easily. With Large 9 cm diameter water inlet, easy to clean, fill water add ice cube. Mouthpiece is 360 degrees rotatable to drink easily. Package Contents: 1 x water bag backpack 1 x water bag Only the above package content, other products are not included. Note: Light different displays may cause the col of the item in the picture a little different from the real thing. The measurement allowed err is 1-3cm.