Well i will let lack of knowledge show up front. I have used the sights that came on my P225 A-1, my P229 and my 365. The sight in the title is new and on an auction local to me. I cannot seem to find info this sight. I see Compact, PRO etc on Sig Sauer's site but I have limited view (pictures) so far. I am going to look at this sight tomorrow and need to know what handgun this will fit. Yep I am clueless on this Romeo-X. Thanks in advance for the help and it is priced at 72.00 so far with the auction ending Saturday.

OK, just got a few pics sent and it says COMPACT on the inside bottom of the sight, so the model question has been solved. Will this sight fit the 229 and 225 or should I just use it on the 365?

I currently have a P229 slide out getting milled for exactly that...a RomeoX Compact. The compact uses the RMSC footprint, whereas the RomeoX Pro is a DPP footprint, and what you'd want for a Sig factory cut slide. If you're getting the slide milled, you can have it cut for whatever optic you want, just be aware that the cut will expose the top of the firing pin block channel, so you'll need to have an optic mounted or a cover plate to use the gun.

In researching my little project, I learned that the window size on the RomeoX Compact and RomeoX Pro are the same...it's just the footprint that's different. It's rather confusing.

The big appeal to me of the RomeoX was the low deck height and ability to use standard-height backup irons with it. I'm still waiting to get it back so can't really speak to the user experience yet.

The Pro model is used for the P226/P229 with optic cuts.

The Compact is for guns like the P365 and other subcompacts.

Perfect! That is what i wanted to know. I will see how I like it on the 365 if I win it.It's brand new so we will see.