Optimal Compatibility: Designed to fit most hydration bladders, these bite valve replacements are specifically compatible with for Osprey Packs Hydraulics Reservoirs. Their universal design ensures they work seamlessly with various brands and types of hydration systems, making them a versatile choice for outdoor enthusiasts. Silicone Quality: Crafted from high-quality silicone, these bite valve sheaths offer exceptional durability and elasticity. They are completely odorless and free from harmful substances, providing a soft, comfortable bite and ensuring a healthy drinking experience during your outdoor activities. Effortless Installation: Replacing your hydration pack's bite valve is a breeze with these silicone sheaths. Simply remove the worn-out valve and pop in the one without any need for modifications to your backpack's drinking tube, making it a convenient upgrade for any hydration system. Comprehensive Package: includes four silicone bite valve sheaths, complete with inner posts. This ample quantity allows for regular replacement, helping to maintain the hygiene and functionality of your hydration system over multiple adventures. Versatile Use: These silicone nozzle replacements are designed to fit a wide range of bite valves, including those that are 360 degrees rotatable and feature on/off functionality. Whether you're biking, running, hiking, or engaging in any other outdoor activity, these sheaths are the perfect replacement for maintaining hydration. :Blue Material:Silicone Package Contents: 4Pack x Bite Valve Replacement Sheath Only the above package content, other products are not included. Note: Light reflection and different displays may cause the of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.