Features: Make of Coppers materials, strong, rustproof, corrosion resistant, can used for long terms. Safety Valves of a water heater is a multifunctional storage type electric water heater safety relief Valves, suitable for electric water heaters and air sources water heaters. It also have the functions of a check Valves and a pressure relief Valves, which can prevent water from flowing back into the electric water heater. Discharge excesses pressure when the pressure inside the electric water heater is too high, ensuring the life of the inner tanks and avoiding the occurrence of bursting accidents. A safety check Valves is used to protect against overpressure in closed water. It determines the flows direction of the medium used, the flows of water, only allows in 1 direction. Specifications: Materials: Coppers Size: about 6x4.2x2.50cm/2.36x1.65x0.98inch Package Includes: 1pc Pressure Relief Valves 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.