These genuine BMW brake pad wear sensors send the signal to your dashboard alert light when the pads start to wear thin. This keeps your rotors in good shape and prevents premature wear from over worn pads. When it comes time to replace your brake pads, make sure you have the proper sensors for replacement.
This replacement front brake pad sensor is needed replacing your worn front brake pads. Some pads do not come with sensors, so a replacement brake pad wear sensor is needed. Replace all of your pads and sensors to give your braking like-new performance.
For the rear brake sensor, please see Genuine BMW E81 E87 E90 E92 Rear Brake Pad Wear Sensor (Inc. 130i, 1M, 335i & M3).