Features: Make of silicone materials, durability and not easily deformed. A thickness of 5mm provides excellent cushioning effect. Suitable for French Horn, Trombone and Tuba. Ensure pure sound quality and more stable performances. The packaging includes 20pcs Rotor Stops, enough for you to replace and use. Specifications: Materials: Silicone Size: As shown in the picture Note: Please allow 1-2cm errors due to manual measurement, make sure that you not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 20Pcs Valves Rotor Rubber Bumper Stop