I've recently gotten a couple of bases for mounting a model of "panda" camera. It comes with a large hole in the back, a threaded hole for 3/8" (I think) conduit or ?? and a threaded hole for 1/2" EMT connectors.
I don't see the use of the (apparent) 3/8" opening. I didn't know this even existed. If there were 3/8" conduit end connectors that thread into a box, this would be that box.
What kind of thing might screw into that hole that looks like it's made for the next size down from a 1/2" EMT?
A good answer is easier with a clear question giving the make and model of everything. "The biggest problem in communication is the illusion that it has taken place." -- G. “Bernie” Shaw