Genuine OEM MINI Exhaust Rocker Arm, part number 11337522124. This rocker arm is a critical component in the engine's valvetrain, responsible for transferring the motion from the camshaft lobe to the exhaust valve. It is made from hardened steel for durability. Genuine OEM rocker arms are manufactured to strict tolerances to ensure proper valve lift and timing, contributing to optimal engine performance and longevity.