●Perfect set: includes 3 litres BPA-free food grade hydration bladder. Each Lunidry waterproof nylon backpack is equipped with adjustable straps, durable and invisible zippers, shoulder straps and a safety reflector on the front of the backpack, which are super durable and reliable for everyday use. ●Keep liquid cool for up to 4 hours: with the special heat-insulated bladder compartment, the Lunidry hydration pack keeps your liquids cool for up to 5 hours, at least 4 hours. Drinking ice water is guaranteed when running, hiking, mountain biking and climbing. ●Multiple storage compartment: includes 2 deep pockets and 1 mesh pocket, enough space to store clothes, mobile phones, wallets, keys, snacks, etc. The front stretch pocket allows you to store more things when hiking, running, cycling, outdoor sports, etc. ●【Leak-proof hydration bladder】: Removable insulated drinking tube with suction mouthpiece, it is easy to drink, pull out the rubber mouthpiece and the water comes out directly. The large opening makes it easy to fill ice cubes, clean and dry. There is even a clip on the right shoulder strap to secure the bubble hose. ●【PERFECT OUTDOOR BACK】: If for any reason you are not satisfied with the Lunidry hydration backpack, please contact us immediately to get a new Lunidry hydration pack or a free bladder.