Radium high-performance radiator caps are engineered to improve cooling efficiency. The radiator cap is an essential part of an upgraded cooling system and will help to safely maximize engine performance by controlling the coolant boiling point. Each OEM replacement radiator cap is manufactured from stamped stainless steel for durability and feature silicone sealing elements that are superior to natural rubber gaskets. Details:-New polish radiator cap design for great looks and performance.-THIS WORKS WITH OE IS300 RADIATORS-Stainless Steel-Silicone sealing components.-Various pressure ratings are available to tune based on coolant boiling point and concentration.