Lixada Lightweight Hydration Backpack 5L Running Backpack Hydration Backpack Waterproof and Breathable Large Capacity Outdoor Riding Backpack Lightweight for RunningLIGHTWEIGHT The hydration backpack is made of quality polyester material which is endurable and light, this professional cycling bag design is different from other backpacks that are a larger figure, it is simple and super lightweight. Equipped with an environmental TPU hydration bladder, pressure tolerant and leak proof. Drink the water by the tube directly without taking your running vest off or stopping your steps. BREATHABLE Excellent air