PERFECT PACKAGE: Includes 3 liter BPA-free food grade hydration bladder. Each waterproof nylon backpack is equipped with adjustable straps, sturdy and invisible zippers, shoulder straps and a safety reflector on the front of the backpack, which have exceptional durability and reliability for a daily use.KEEP LIQUID COOL FOR UP TO 4 HOURS: With the special heat-insulated bladder compartment, the hydration pack keeps your liquids cool for up to 5 hours, at least 4 hours . It is guaranteed that you can freely drink ice water while running, hiking, mountain biking and climbing.MULTIPLE STORAGE COMPARTMENT: Includes 2 deep pockets and 1 mesh pocket, enough storage space to store clothes, phones, wallets, keys, snacks, etc. Expandable front pocket allows you to store more stuff while hiking, running, cycling, outdoor sports, etc.LEAK-PROOF WATER BLADDER: Detachable insulated hydration hose with mouthpiece mouthpiece, it is simple to drink, pull the rubber mouthpiece and the water comes out directly. The large opening makes it easy to add ice cubes, clean and dry. There's even a clip on the right shoulder strap to help secure the bladder hose.PERFECT OUTDOOR BACKPACK: If for any reason you're not happy with the hydration backpack , please feel free to contact us immediately to get a new hydration backpack or free bladder.