This plug is for use on all Delphi radios and some heavy-duty Panasonic radios for the following applications: Kenworth medium duty COE models. Kenworth conventional models February 1994 - April 2005. Peterbilt medium duty 330 COE and conventional models. Peterbilt COE models 1986 and newer. Peterbilt conventional models October 1986 - June 2005.