The Two Litre Hydration Pack is lightweight and easily collapsible, perfect for using with your hydration backpack. With a durable drinking tube and design, it's perfect for hikers and runners. Composition - This product is designed in tough TPR. Perfect for outdoor use BPA Free - This bottle is free from BPA (Bisphenol A), a chemical used to make food containers and bottles Bite Valve - Bite down for instant refreshment when on the moveHydration Compatible - The pack is compatible with a 2 litre hydration compartment in your backpackCompact - Folds away small, making it simple to store away when not in use