1. Running Hydration Backpack - This running hydration vest is designed for running road cycling hiking. The backpack weighs 250g 8.82oz, which is ultra-light and greatly reduces the burden when running. The running vest is made of nylon stretch fabric, which is comfortable and durable. 2. Comfortable back system - The lightweight cycling backpack back lining and shoulder straps are made of lightweight and breathable mesh fabric, which can speed up air circulation and keep your back dry and comfortable when hiking. Soft shoulder strap edges prevent the backpack from chafing your skin. 3. Ergonomic and Contoured Design - The ergonomic hiking backpack hydration vest adjusts to your back while gently protecting your muscles. The adjustable chest strap and waist belt reduce the burden on your shoulders, making the backpack fit perfectly, reducing bounce and maintaining balance. 4. 6 secure storage pockets - The running vest has a total of 6 external pockets with a capacity of 5.5L, the water bottle compartment on the chest can accommodate two 250ML soft water bottles, and the hydration compartment on the back is compatible with a 1.5L water bag. The remaining pockets allow you to store small items such as keys, mobile phones, tissues and cash. These pockets can also protect your valuables, which is very practical and convenient.