FEATURES eep Liquid Cool up to 4 Hoursith the special thermal insulation compartment, G4Free Hydration Pack keeps your liquid cool for up to 4 hours. You can drink icy water freely in running, hiking, climbing, and mountain biking. ightweight & Comfortablenly 1.1lb/500g. Made of high-quality nylon, more durable use. A breathable air back panel keeps your back cool, adjustable chest strap with whistle and waist strap perfectly fit your body. This hydration backpack is super comfortable, breathable, lightweight, compact, and low-profile, you wont get any burden in running or cycling. The waist size is up to 50inch. Leak-proof Water Bladder switch valve and a cover cap make double leak-proof. Hands-free hydration hose with suck mouthpiece, gently biting to get the liquid to flow. The large opening makes it easy to add ice cubes, clean and dry. With this BPA-Free, taste-free, and odorless hydration bladder, you can keep hydrated and active all day throughout your adventure. ultiple Storage Compartment Include 2 deep pockets and 1 mesh pocket, enough space to carry your clothes, keys, snacks, phones, wallet, etc. With the additional bungee straps, you can easily carry your bike helmet or wet towel. Reflective tapes for better safety. our satisfied outdoor backpack for any reason you are not 100% satisfied with Hydration Pack, please contact us freely and we will try our best to solve it well for you.