Outdoors Sport Hydration Pack - Backpack and 2-Liter Water Bladder Included LIGHT WEIGHT & COMFORTABLE  Made of lightweight, breathable mesh with ergonomically correct straps fit comfortably on the shoulders. Size: 15.75 x 7.87 x 2.76 inches. 2 liter BPA-free water bladder included. EXTERNAL COMPARTMENT  Our mesh pocket lets you stay hands free while running. There is plenty of room for your keys, wallet, cellphone or energy bar. DURABLE - Tired of hydro packs that come apart and don't last? The rip-stop polyester material makes this backpack resistant to water and durable over time. STAY HYDRATED FOR PEAK PERFORMANCE  Generous 2 liter capacity makes this he perfect choice for running, hiking, biking, or any daylong activity. Maintain peak performance by staying hydrated. MONEY BACK GUARANTEE: If you decide the product isn't for you at any time in the first 6 months, you'll receive a full refund of your purchase price.