M3 stylus with 0.5 mm diameter ruby ball, 0.4 mm diameter carbide stem, and 4.0 mm diameter x 19.0 mm long tapered stainless steel base. Overall stylus length is 21.25 mm. Stylus weight is 0.89 gram. Compare to Renishaw A-5000-7632, Mitutoyo K651111, and Carbide Probes 261-.5R.