This adaptor is to be used in conjunction with a 12v DC Power supply (not included) such as AC001 in our Accessories section and is used to power the FCR away from the vehicle when updating Firmware or changing a licence for a new vehicle from the originally licensed one. Simply plug into the 9 way port on the FCR and then to a 12V DC supply via the units DC socket to power the FCR while not connected to the vehicles OBD port.