This item is discontinued!
This Luthier Digital Caliper has 2 differences with the regular calipers, one is it has a notch on the jaw that is for measuring fret wire crown height, and the second is there’s another notch on the caliper end (the depth gauge), it’s for measuring the fret height that has installed on the instruments.
It features a digital indicator with a zero button and inch/mm/fraction switch button, 6” (150mm) long, battery and plastic case are included.