GRANDCOW 2L Water Bladder Bag Backpack + Hydration Water Bladder for Hiking Camping 2L Outdoor Sport Cycling Bicycle Bike Hydration System Backpack Bag + Hydration Water Bladder for Hiking Camping. Reservoir is great for upgrade or replacement of your current reservoir. Eco-friendly TPU material,safe to us, odorless, tasteless. Bite Valve Cover keeps Bite Valve clean from dirt. Come with a switch on/off bite valve, convenient for control the flow of water. Fit most Hydration System & Military Combat Vest. Outdoor sports supplies water reservoir bag, for cycling, climbing, hiking etc.