What kind of vintage video connector is this?

[andrewcless]

I recently found a pair of Sanyo vm 4209 displays and I and not sure what kind of video connector they have. The connector is a fairly large analog threaded video connector that looks kinda like a scaled up cable tv connector. Please help.

 

[clutchc]

I think it is a "uhf pl259", but of course I can't be sure. See if these look like it.
https://www.amazon.com/s/?ie=UTF8&keywords=uhf+pl259&tag=googhydr-20&index=aps&hvadid=229156960692&hvpos=1t1&hvnetw=g&hvrand=15461862488699734501&hvpone=&hvptwo=&hvqmt=e&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9016202&hvtargid=kwd-301514021161&ref=pd_sl_6tnqtxzvcr_e_p37

It's pretty old and I never owned an Apple I or II system, if that is what the monitor belongs with.