Mercedes ,GLA, GLB, GLC, GLE, and GLS models. It includes one sensor with a clip-on or bolt-on mounting style, suitable for front or rear placement. The sensor features ultrasonic technology and comes with a decoupling ring for easy installation. It is wired with a 3-wire quantity and requires calibration using a diagnostic tool. The sensor is backed by a 2-year manufacturer warranty and is a performance-enhancing part.