Made of food grade TPU material, 100% odorless and BPA free, SGS certified. Passed full strength test and vibration test. The wide leak-proof mouth is easy to clean and add ice. Close the on/off valve to regulate the flow of water, and the padded valve makes it easy to drink. Ergonomic design, comfortable to wear--Ergonomically designed hydration backpack is suitable for to different body types, the 4 wide shoulder straps are adjustable to fit perfectly, prevent the bag from shifting and reduce bouncing. Durable shoulder straps are soft and comfortable so you feel less pressure while keeping your balance. Breathable and lightweight hydration pack-- Made of ultra-lightweight, waterproof and durable nylon fabric tear-resistant, it wont impede your movement during exercise, with low resistance, allowing your body to maintain peak performance. The back and shoulder straps are designed with mesh and perforated EVA with ventilation channels to accelerate air circulation and cool the back. Breathable material for running or cycling backpacks that will meet your needs. Excellent storage and insulation-- The hydration pack for men/women has multiple pockets, enough space for store most outdoor items. Front and rear reflective strips are designed to protect you when running or riding in the dark. Trail bags include an insulated bag to keep your water hot and cold for hours. Outdoor Sports Accessories-- The running hydration backpack is specially designed for the cycling, running, mountaineering, hiking, rock climbing and kayaking. The perfect gift for anyone who loves the great outdoors.