Genuine OEM Jaguar Rocker Arm, part number C2C21308. This critical engine component is responsible for transferring the motion from the camshaft to the engine valves, allowing them to open and close at the precise moment. It typically works in conjunction with a hydraulic lash adjuster to maintain zero valve clearance. Genuine OEM rocker arms are manufactured to exact factory tolerances, ensuring smooth operation, reduced friction, and a long service life within the demanding environment of the engine's valvetrain.