(4) Pressureproof and Leakproof Quick Release Tube - Removable insulated drinking tube is with -in connection instead of old one,it is not get loose to cause leakage and easily quick dry,the 2L hydration bladder has a detachable tube that can be operated by one hand,when the tube is disconnected,the shutoff valve closes and the bladder doesn't leak at all,military-grade double sealing lines are added on the edge of the water bladder to make sure the bladder is pressure tolerant and leakproof.