Unigear Hydration Packs Backpack with 2L TPU Water Bladder Reservoir, Thermal Insulation Pack Keeps Liquid Cool up to 4 Hours for Running, Hiking, Climbing, Cycling PREMIUM MATERIAL and THERMAL INSULATION FUNCTION: Adopt 210D ripstop material in main areas and combine with smart design to create a lightweight and tough pack that will last a lifetime. Thermal insulation function in bladder compartment keeps you drinking cool and fresh water on your trail. Selected premium buckle, SBS hidden-teeth zippers and other accessories, enjoy your ride with confidence and take your trail skills! FDA-APPROVED 2 Liter TPU BLADDER INCLUDED: Manufactured from high quality TPU flexible food grade material, its BPA free. The Low-Profile fit for unmatched stability which reduces liquid movement for increased pack stability at high speed. An ergonomic handle and 4" opening for easier refilling cleaning, and an O-ring Gasket Built in tube connecter and on/off lever that makes it easy to prevent leaks. VENTILATED BACK PANEL and COMPRESSION STRAPS: Body-mapped and super-breathable materials for maximum comfort and ventilation. Thicken and widen Ergonomic mesh-covered padding with ventilated EVA foam, allowing air to circulate and helping absorb impact in a crash. The adjustable sternum straps and upper side compression straps in compressing and stabilizing loads for optimal carry and fit. REFLECTOR and MULTIPLE THOUGHTFUL DESIGNS: Multiple organizations allow you to stow and secure your gears in order. A lumbar pocket design optimizes and shifts your load to your hips for a lower center of gravity and more freedom of movement and gives you better balance on steep, technical terrain. The helmet carry system allows a bike helmet to be quickly and securely stored and reflective logo/strips keep you visible in low-light environments. PERFECT OUTDOOR COMPANION: When you use our gear, youre taking an extra friend with you on your adventures. Uncomplicated and Comfortable! Unigear offer 60 days 100% Satisfaction Guarantee and if you are not 100% satisfied with this product for any reasons, please contact our customer service and we will immediately refund your purchase price - no questions asked.