Hydration pack have thick insulated layer ,the insulated bladder compartment to keep water cold for hours.PROFESSIONAL 3L water backpack: The mouthpiece has been upgraded to an easy ON/OFF push valve and designed to help stop leakage. Simply bite the mouthpiece to suck water, Conveniently control the water flow by biting.Our water bladder have passed pressure tolerated tests ,SGS certified and food gradeThis Hydration packs are designed specifically for road cycling /running/ Hiking ,So that's Compact and low-profile so they feel light and stable on your back and won’t create a ton of wind resistanceThis Hydration Backpack comes with 3-Liter water bladder & hose outlets designed to free your hands.we have done 100% checking work to promise a perfect experience for you. If you are not satisfied with the backpacks you purchased, please feel free to contact us. We will give you a satisfactory solution within 24 hours. To buy is to earn! A decent Holiday Gift for someone you love, especially yourself! Click ‘BUY IT NOW’ to experience it!! Product Description Track Page Views WithAuctiva's Counter