This is the M3 tungsten carbide styli for Zeiss #A-5555-0263. It has a stainless steel base, tungsten carbide stem and ruby ball.
| Styli | M3 |
| Ball Diameter (DK) | 3.0 mm |
| Length (L) | 40.0 mm |
| Base Diameter (DG) | 5.5 mm |
| EWL (ML) | 21.5 mm |
| Stem Diameter (DS) | 2.0 mm |
| Stem material | Tungsten Carbide |
| Mass | 4.0 g |
