M3 stylus with 0.5 mm diameter ruby ball, tapered carbide stem, and 5.0 mm diameter x 9.0 mm long titanium base. Minor stem diameter is 0.3 mm, major diameter is 1.0 mm. Overall stylus length is 20.0 mm. Stylus weight is 0.55 gram. Compare to Renishaw A-5004-2186 and Zeiss 626113-0050-020.