Materials: This automotive engine thermostat is made of ABS and metal, offering durability, wear resistance, and high strength, ensuring long-term use Function: By regulating the amount of coolant entering the radiator, the engine operates at the appropriate temperature, reducing engine wear, deposits, and emissions For Astra 55593034 Engine Coolant Thermostat Features: The smooth of the thermostat not only ensures stable engine temperature but also reduces wear on other related components. Function: This thermostat prevents overheating and maintains the engine at an operating temperature, extending vehicle and reliability.