•For all cars with 10mm, 12mm, 9/16” jam nut valve screws.
•Each tool includes an idle adjustment screwdriver within socket with window and a different handle for holding adjustment screw in place.
•The socket ” window ” is always visible when handle pivots from one side to the other, see the  position of screwdriver blade holding the adjustment screw while the jam nut is tightened.
•Primarily for ” VW ” and ” Porsche ” cars with 13mm jam nut valve screw.
 

•For all cars with 10mm, 12mm, 9/16” jam nut valve screws.
•Each tool includes an idle adjustment screwdriver within socket with window and a different handle for holding adjustment screw in place.
•The socket ” window ” is always visible when handle pivots from one side to the other, see the  position of screwdriver blade holding the adjustment screw while the jam nut is tightened.
•Primarily for ” VW ” and ” Porsche ” cars with 13mm jam nut valve screw.