Thread: CZ527 with threaded muzzle

Hello people, some wise council.

I have a CZ527 American, in .223. It has a 20 inch barrel with a threaded muzzle. I do not know if CZ ever made this model threaded for a suppresser. I am assuming that someone had it done afterwards, although maybe I am wrong.

If I were to want to get a supressor to have a play with, how do I tell what pitch or size the thread is.