I have a P320 AXG that I built, I've run both a ROMEO 1 X PRO and a ROMEO X Pro Enclosed. I ended up running the R1XPRO on the P320 and put the XPRO Enclosed on my P220. Both worked on the P320, however, aesthetically, I like the Enclosed on the P220. The 1XPRO doesn't sit flush with the slide on the sides, sticks out a bit.