This is the M2 ruby stylus #A-5003-3822. It features the tungsten carbide stems.

This straight stylus can be used for simple features with which direct contact can be made. The tungsten carbide stem provides exceptional rigidity, particularly for styli with small stem diameters. Ruby tips are very hardwearing and are ideal for most standard applications.

Equivalent to Zeiss part number: 602030-8005-000