M3 stylus with 0.5 mm diameter ruby ball, stepped carbide stem, and 5.0 mm diameter x 9.0 mm long titanium base. Major stem diameter is 1.0 mm, minor diameter is 0.3 mm. Overall stylus length is 13.0 mm. Stylus weight is 0.53 gram. Compare to Zeiss 626113-0050-013 and Renishaw A-5004-1702.