M3 stylus with 0.6 mm diameter silicon nitride ball, stepped carbide stem, and 4.0 mm diameter x 6.0 mm long stainless steel base. Minor stem diameter is 0.4 mm; major diameter is 1.0 mm. Overall stylus length is 20.0 mm. Stylus weight is 0.51 gram. Compare to Zeiss 626123-5545-020.