Used primarily for the precise measurement of radius of curvature of curved surfaces such as lenses and mirrors. Brass disc of about 40mm diameter, graduated 100 divisions, rests on the center of a three pronged brass table, through a steel screw. Each prong carries a pointed leg of MS below it equidistant from each other. A vertical scale, graduated 10-0-10mm mounted on one of the prongs.Screw Pitch 1mm, LC 0.01mm

INCH10034/1 Screw Pitch 1mm, LC 0.01mm

INCH10034/2 Screw Pitch 0.05mm, LC 0.005mm