Brake pad wear sensor. Sold individually. Fits many Mercedes models in different locations:
- W211 - Front Right & Rear Right (Front Left uses different sensor)
- W164/X164/W251/X204 - Front Right & Rear Right (no left side sensors)
- W166/X166 Rear Right (Front sensors are different)
- W212 - Front Right & Rear Right (no left side sensors)