M2 star center stylus with 0.5 mm diameter ruby ball, stepped carbide stem, and 3.0 mm diameter x 5.0 mm long stainless steel base with captive screw style thread. Minor stem diameter is 0.4 mm, major diameter is 0.7 mm. Stylus length to ball center is 18.75 mm. Stylus weight is 0.41 gram. Compare to Renishaw A-5003-4790.