This is a Taper Shank BT50 for OMP40 and OMP400 #M-4071-0071. This shank is designed to secure the probe into a BT ISO 50 taper machine tool spindle. Shank gauge length is 51.00 mm (2.008 inches), and it is suitable for OMP40 and OMP400 probes.
(M-4071-0071) Taper shank: shank specification BT-1982, taper ISO 50
M-4071-0071 | Machine Tool Probes | Taper Shank | BT50 shank for OMP40 and OMP400 | Renishaw