This Valvetronic timing actuator motor is designed for N20 and N55 engines.It is compatible with a range of models including the 135i, 228i, 320i, 328i, 528i, 535i, X5, and X6.The component functions within the Valvetronic system to adjust camshaft timing.It is engineered to meet functional specifications for proper of the variable valve timing mechanism and fits vehicles equipped with N20B20A and N55B30A engine variants.Each unit undergoes pre-shipment testing to verify functionality.Compatible part numbers include 1377603979, 11377599021, 11 37 7 599 021, and A2C5328032080.