KEEP WATER COLD The hydration pack has a thick insulated layer, the insulated hydration bladder compartment keeps your liquid cold or warm for up to 4 hours.COMPACT & LIGHTWEIGHT These hydration packs are specially designed for road bike/running/hiking, so they are compact and lightweight, so they feel light and stable on your back and reduce wind resistance, keep your body working at peak performance whether you are training for a marathon or cycling.Professional 2 litre hydration bladder. The hydration bladder is made of high quality TPU material. Water bag is tasteless, odorless, BPA free, SGS and FDA approved. Our hydration packs have passed the pneumatic pressure test, 24-hour swing test and 24-hour vibration test. Large opening is easy to clean and add ice cubes. 135 degree rotating mouthpiece allows easy drinking. Shut-off valve helps to adjust the water flow.COMFORTABLE & RELIABLE Ergonomically fit your shoulders, chest and waist, 3 straps are all adjustable to reduce bounce, you never lose our balance due to the water load, soft air mesh back accelerates air flow and makes your back cool. Foam padded shoulder straps are extremely comfortableVERSATILITY & 100% SATISFACTION AFTER PURCHASE The hydration pack is your perfect choice for cycling, camping, running, music festival, rave, kayaking. A nice holiday gift for families and friends who love outdoor sports.