SAFETY PROMISE -- 100% BPA and PVC Free, the hydration bladder is comply with all relevant safety standards. Tasteless, eco-friendly PEVA and TPU material can be recycled easily. Compatible with most hydration backpacks. SPACE SAVING DESIGN -- Compact water bladder design and built for a long life for durable use. The water reservoir stands upright when it full and shrinks in the min volume while empty, perfect for space-saving. Feel free to drink or fill it. The more you drink, the smaller it is. EASY DRINK -- Light suck gives ample hydration. Drinking water by the soft bite valve directly without stopping your steps or taking off your running backpack. Convenient hydration reservoir for your outdoor Marathon, Running, Hiking, Cycling, Climbing. PRACTICAL WATER BAG -- Both the top opening and the bottom connection features leak proof design. Wide-mouth opening with slide lock closure strengthened leak-proof, and makes it easy to refill, clean and dry inside the hydration water bladder. EASY CARRYING -- Ultra-light water storage bladder bag is portable enough to follow you anywhere. It can be put compactly in your hydration vest. Great backpack reservoir replacement for kids and adult. Specification: Material: PEVA, TPU Color: Blue Package Includes:(2 Pack) 1 Piece Hydration Bladder