The 250-4369 is a speed signal adapter/divider. In some vehicles ( mostly Chrysler 2003 and up automatic transmission ) the speed signal output is too fast for the 250-1223 electronic servo to read. This part divides that signal by 3. If your Chrysler vehicle is a 2003 or newer, is an automatic transmission and has 4 connectors ( NOT 3) on the PCM, than you will need this adapter.