• Easy filling and cleaning: The big opening make for easy pouring of water.
• Design with double sealing to make sure will not leak. Firstly, pinch and seal the TPU clip chain, then add slide-seal system. 
• Water reservoir is pressure-tolerant and wear-proof, manufactured with leak proof sealing technology and high smooth interior surface.
• Clean food grade TPU material: Taste free, non-toxic, the whole hydration bladder is made of premium anti-bacteria material for free mouthpiece. 
• The on-off valve at the top mouthpiece can control the water flow. And the bite valve will auto-seals after each sip
• The mouth piece uses a bite valve technology that makes it easier to drink.
• some people call these camelbak. It's a famous global brand but we are not affiliated.