For using on all 10mm, 12mm, 13mm, 1/2" and 9/16" jam nut adjustment screws.

This universal valve adjustment tool has been designed for a wide variety of cars with 10mm, 12mm, 13mm, 1/2"and 9/16" jam nut valve adjustment screws.

This two in one tool features a window in its socket so the technician can see the position of the screwdriver blade holding the adjustment screw as the jam nut is tightened.

This visual contact in addition to the feel of holding the screwdriver allows for quicker valve adjustment times as the technician can hold the adjustment screw exactly where he wants it.