When Renishaw developed the small touch trigger probe (TP2), it attached to the CMM ram via a probe head with a threaded M8 connection in line with the probe body itself. However, this design required a probe recalibration whenever it was removed or reattached.
To alleviate this need to recalibrate, Renishaw developed a quick-connect adapter (termed QuickConnect) which used a ΒΌ turn of a key to lock and unlock the adapter from the CMM. The TP2 screwed into this adapter. This adapter could be detached and re-attached very quickly and repeatably without the necessity of always recalibrating.