Model: CLS550. Part: ABS Wheel-Speed Sensor and Suspension Height Level Sensor Harness. OEM Part Number: A2125402705 — Rear Suspension Height Level Sensor Wiring Harness. The markings confirm that this assembly contains two different OEM-numbered components: A2125402705 is the electrical harness for the rear suspension level sensor, while A2125402117 identifies the rear wheel-speed/ABS sensor.