M3 stylus with 0.3 mm diameter carbide ball, stepped carbide shaft, and 4.0 mm diameter x 5.0 mm long stainless steel base. Major shaft diameter is 1.0 mm, intermediate shaft diameter is 0.5 mm, minor shaft diameter is 0.2 mm. Overall stylus length is 15.0 mm. Stylus weight is 0.49 gram.