This is a universal speedometer gear counter for Ford C4 C6 AOD AODE A great tool to have when you dont want to take the transmission apart to get your drive gear count and when gears are worn to a point of being unable to read. When placed in the extension housing and meshing the gears with the output shaft you simply turn the output shaft exactly 2 full turns and the counter points to the number of spiral teeth cut into the output shaft. Dont get complaints that your speedometer is off any longer! Instructions are available with purchase. NOTE: There are color variations