This particular adapter is designed to prevent electrical accessories from interfering with the electrical system on the late model BMW, and other European motorcycles with a Can-Bus electrical system and a “City Light” 194 marker bulb in the headlight.The Denali Electrical Can-Bus Connector includes built-in reverse polarity protection. This item is designed purposely to provide a “hot” trigger wire to activate a relay to power other accessories, such as driving lights, accessory fuse blocks, GPS, or other 12-volt electrical devices when the motorcycle is turned on without upsetting the motorcycle's sensitive CAN-BUS system. This adaptor is also removable without leaving holes in the insulation of the original wiring harness, so it keeps your warranty in places even at the strictest dealers. Installation is very simple: 1. Remove the socket from the headlight housing. 2. Unplug the bulb from the socket. 3. Plug the circuit board into the socket from where you just removed the bulb. 4.