This brake light switch, also referred to as the stop light switch is mounted to the brake pedal assembly. If it is faulty it can cause the brake lights to malfunction. BMW produced 2 versions of this part - 4 pin & 2 pin. Please check your car to ensure that you are ordering the correct part. This is the 2 pin switch.

This item fits the following BMWs:
1984-1991 E30 BMW 318i 318is 318ic 325e 325es 325i 325ic 325is 325ix M3
1992-1998 E36 BMW 318i 318is 318ti 318ic 323is 323ic 325i 325is 325ic 328i 328is 328ic M3