This is the ISO40 DIN69871 Shank #M-4071-0069. This shank is designed to secure the probe into a DIN69871A ISO 40 taper machine tool spindle. Shank gauge length is 41.60 mm (1.638 inches), and it is suitable for OMP40 and OMP400 probes.
Taper shank: shank specification DIN 69871A, taper ISO 40
M-4071-0069 | Machine Tool Probes| Taper shank | ISO40 DIN69871 | ISO40 DIN69871 Shank | Renishaw