OE 12372-28210 is a Toyota left-side engine mounting insulator for transverse-engine applications. It combines a rubber vibration isolator with a steel structure to support the engine/transmission assembly, reduce vibration and impact transferred to the body, and control excessive powertrain movement during acceleration, braking and gear changes. It is mainly used on selected third-generation Toyota RAV4 models with 1AZ-FE or 2AZ-FE engines and 5-speed manual transmission.