Equipped with a tube with a bite valve to drink, you do not have to hold it to drink. Constructed with waterproof 600D Nylon material, the backpack is wearable and durable. Completed with a switch on/off bite valve, it's convenient for you to control the flow of water. With the adjustable shoulder strap and chest strap, it's suitable for heavy carrying and secured enough so that will not distract you when you do some exercises. About 460g(16.23oz), the Hydration Pack is light weight and suitable for running, hiking, hunting, climbing and other outdoor activities.