M3 stylus with 0.3 mm diameter silicon nitride ball, tapered carbide stem, and 4.0 mm diameter x 5.0 mm long stainless steel base.  Minor stem diameter is 0.2 mm, major diameter is 1.0 mm.  Overall stylus length is 18.0 mm.  Weight is 0.52 gram.  Compare to Zeiss 626123-5245-018.