[Romeo 1 Pro]

 
Same bolt pattern and size as a DPP, but doesn't have any locator boss/pin pockets in the underside. So if you have a mount/gun where those are integral, the R1Pro won't fit without modifying something

Good to know, thanks. And I agree, annoying....

[Romeo 1 Pro]

Looking at an R1 Pro, but had a question.   Is the bolt / mounting pattern the same as something like a Leupold DPP?   I have a P320 X5, but also looking to get a G20 slide milled (more for woods / hunting use).  Ideal scenario is there's some interchangeability if I end up with multiple sights, but at least want to know what I'm getting into...