Okay, thanks. I wish the slide manufactures would list the sight height needed for either co-witness or lower 1/3 co-witness. Lol. From what I’m seeing is there’s little standardization with mounting pistol optics. It seems many are gravitating to the Trijicon RMR which is why I chose slides with the RMR cut. I think Glocks optics mount is called MOS.?.? I’ve been told for example that whatever optics cut that Shadow Systems uses, that it mounts the optic much lower than Glocks optics mount, and that it allows them to use standard height sights. Maybe I should of just gone with a XR920 instead of do big spending on a nice P80 9MM.