1、Excellent Compatibility: The bite valves are compatible with most hydration bladders. These bit valves are safe and durable to use. Give you a better use experience. 2、Well Sealed: Self sealing bite valves have one piece construction so there are no water drips. Durable and soft for wholesome flow from your water bladder. 3、With Shutoff Valve: Easily control waterflow with the yellow lever. Compatible with drinking tubes and bite valves of most hydration bladders. 4、Food Grade Silicone: Made of food grade silicone, these mouthpieces are safe and reliable, non poisonous, odorless and harmless to human body. 5、What You Will Get: There are five mouthpieces and a shutoff valvein cluded in the package so you can use your backpack reservoir for a long time.