1.Precise Sealing: The whole edge of the body of this 1.5L/2L bladder adopts double-welded side quilting design to withstand a high degree of compression. One end of the water tube is a self-sealing mouthpiece, and the other is an automatic locking connection plug whose waterproof ring has been formed and fitted tightly. When the water pipe is inserted, it can be automatically locked quickly and won't loosen. 2. PREMIUM QUALITY: BPA free, food grade EVA material plus TPU The drinking tube makes the whole water bladder tasteless. The water bladder has passed the pneumatic pressure test, the double side sealing technique has greatly improved the durability. no extra space is used. Besides that. Large opening makes it easy to fill/pour water. Also can put big ice cubes in the water bag to keep the water cool. drinking tube attached to the hydration bladder, staying hydrated is now simple. Just bite the mouthpiece to suck the water. Soft mouthpiece with easily accessible ON/OFF valve to prevent leaks. It also has a lid to keep dirt out. Easily control the water flow by biting, when it does not bite, the water will not leak. , etc. It's a must have for sports enthusiasts and an ideal gift choice.