Installing LED bulbs may in some cases interfere with a vehicle's electrical system causing stereos and radios to hum. To resolve this issue, install this radio noise canceller between the OEM plug and the LED driver to eliminate the noise. This is a plug-n-play design for H1, and H3 connectors. Add one noise canceller to each LED bulb to eliminate electro-magnetic interference noise (EMI). Plug'n'Play connection. Works with H1, and H3 LED bulbs.