The Bridgeport is RH I made a stop or two and used a regular tap to make the
threads. Sure is handy. I hated to run that factory stop up and down, you can
only turn it about a half turn at a time and it takes FOREVER to move a ways.
...lew...
The hole is theaded and the two halves are hinged with a spring to close them; you open it up and clamp it onto the threaded rod at the level you want. I just ordered one from Enco yesterday.