Feature: 1. The backpack is equipped with a built-in water bladder compartment, freeing up your hands. Riders can replenish their hydration in a timely manner while riding. 2. The breathable mesh back panel is more comfortable to wear and reduces the burden of exercise. 3. It is compact and low-profile, providing a light and stable feel on your back while minimizing wind resistance. 4. The backpack adopts a breathable mesh design, which can quickly dissipate sweat and heat. 5. This hydration backpack is suitable for hiking, running, mountaineering and outdoors. Specification: During a long hike having water so convenient and still cold…there’s nothing like it. Lightweight with a custom fit, you’ll forget you have it on until you need it. This hydration pack give you plenty of water for your day hike. Features: The backpack is equipped with a built-in water bladder compartment, freeing up your hands. Riders can replenish their hydration in a timely manner while riding. The breathable mesh back panel is more comfortable to wear and reduces the burden of exercise. It is compact and low-profile, providing a light and stable feel on your back while minimizing wind resistance. The backpack adopts a breathable mesh design, which can quickly dissipate sweat and heat. This hydration backpack is suitable for hiking, running, mountaineering and outdoors. Specifications: Material: Nylon Color: Green/ Blue/ Black/ Red (optional) Size: 43*27*6cm/ 16.9*10.6*2.4in Weight: 300g/ 10.6oz Package list: 1 * hydration backpack Package List: 1 * hydration backpack