Optimal Compatibility: These replacement bite valves are designed to fit most hydration bladders and are specifically compatible with Packs Hydraulics Reservoirs. Their universal design ensures they work seamlessly with a variety of hydration systems, making them a versatile choice for outdoor enthusiasts. Superior Silicone Quality: Made from high-quality silicone, these bite valves offer exceptional durability and elasticity. They are completely odorless and free of harmful substances, providing a soft, comfortable bite and ensuring a healthy drinking experience during your outdoor activities. Easy Installation: Replacing your hydration backpack bite valve is easy with these silicone ones. Simply remove the worn-out valve and insert the new one without having to make any modifications to your backpack's drinking tube, making it a convenient upgrade for any hydration system. Comprehensive Package: Includes four silicone bite valves, complete with inner posts. This ample amount allows for regular replacement, helping to maintain the hydration system and functionality over multiple adventures. Versatile Use: These silicone mouthpiece replacements are designed to fit a wide range of bite valves, including those that are 360 degrees rotatable and have on/off functions. Whether you are cycling, running, hiking or participating in any other outdoor activity, these are the perfect replacement to maintain hydration. Color: Blue Material: Silicone Package Contents: 4-Pack x Bite Valve Replacement Covers The above package contents only, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3 cm.