I have the bulb in a circular BM halogen lamp in use. Unfortunately, the bulb lights up only way forward, whereby the light is not really strikes the mirror. It therefore forms no forward focused beam. But since I have the lamp mounted as a second lamp I am very satisfied. The main lamp with halogen now no longer constantly burning due to overvoltage by and brings focused light on the road, the new LED bulb illuminates the environment and the local area and ensures that I am well seen by car.