elevation gear and pin set. Figure #83 / 84 in the parts list for the 23C, 23CII, 23CII XL, 67CS, 67SC, and 67SD enlargers. It is recommended that the elevation gears be replaced as a set. Made by Charles Beseler USA.
Exploded views for the 23C
can help you find the part you need.
to select the number of gear/pin sets needed.