The Park Tool Digital Caliper Accessory Jaws add protruding contact point to the caliper jaws for accurate measurements of brake rotors and items where the leading edge may skew readings. They also add conical end points that eases the process of measuring center to center distances of bolt holes. Features: Protruding contact points allows for the measurement of the center of the braking surface, bypassing the unworn edge to ensure an accurate measurement Installs onto most digital, dial, or vernier calipers (including the Park Tool DC-1) protruding contact points that allow