The extensions have cone-shaped tips that align perfectly with the inside edge of the caliper jaws, which lines the jaws up with the center of each hole. You read the center-to-center distance ...

In disc-brake systems, a caliper is a set of metal jaws that clamps down on a wheel’s brake disc, or rotor, when the driver applies the brakes. The caliper presses brake pads against either side ...

The business end of a Vernier caliper. The Vernier scale is on the lower part of the sliding jaw. A Vernier caliper is a graduated sliding clamp usually over 150mm long, with a Vernier scale that ...