The DCA-1 installs onto most digital, dial, or vernier calipers (including the Park Tool DC-1) and features protruding contact points that allow measurement of the centre of the braking surface, bypassing the unworn edge to ensure an accurate measurement
The conical end points of the DCA-1 can also be used to measure centre-to-centre distances of bolt holes for calculating bolt circle diameter (BCD) of chainrings and cranks
