This is the RMP60M probe module #A-4038-1002.

It enables probe inspection of part features that would be inaccessible to the standard RMP60. It allows fitment of adaptors, extensions and Renishaw’s LP2 touch probe. The RMP60M is a modular version of the RMP60. The RMP60M, probe module, adaptors and extensions need to be purchased separately. RMP60 complies with FCC regulations and operates in the 2.4 GHz range.