M3 stylus with 0.5 mm diameter carbide ball, carbide stem, and 4.0 mm diameter x 10.0 mm long stainless steel base. Minor stem diameter is 0.3 mm, intermediate diameter is 0.6 mm, major diameter is 1.0 mm. Stylus length to ball center is 21.0 mm. Stylus weight is 0.88 gram.