This is a fuse adapter that is needed to perform all lost keys with the Diagspeed through the OBD in the car.
Reference the manual for connection to each model series. Makes a quick easy process for doing a data read in the car. Now allows for 15-20 mins in the car for w204, w207 , 172 , w212 chassis cars.
Its a must tool if you have had the Diagspeed tool for a while and need to add on this must have cable.