Features: Make of heat resistant and corrosion-resistant ABS and rubber materials which can perform well under various pressures and temperatures. This antinegative pressure None return rubber pad have a unique design which can effectively prevent the water pressure rebounds caused by negative pressure. It requires no special tool or complicated step and can easily replace it in your own bathroom. This None return rubber pad is specially designs to provide excellent sealing effect which can effectively prevent water or air leakage. By using our None return rubber pad you can improve your water efficiency. It can ensure the smooth flows of water and prevent the water pressure from being too low. Specifications: Materials: ABS and rubber Quantity: 2pcs/6pcs/12pcs Size: about 2.5x1.7cm/0.98x0.67inch Package Includes: 2pcs/6pcs/12pcs Shower Faucet Gasket note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to difference between different monitors, the picture may not reflect the actual color.