NOTE: OPF-G43x/48, RMRcc is designed for and only compatible with Glock 43x and 48, and Trijicon's RMRcc. It will not work with other Glock models, and other sights. For law enforcement and users that require backup sights, Ameriglo GL-527 (front sight height 0.450", rear sight height 0.554") will be needed for lower 1/3 co-witness.
OPF-G43x/48, RMRcc (Optics Platform, Forward Controls, G43x/48, RMRcc) is the latest member of the OPF line. G43x and 48 MOS slides are designed for direct mounting of the Shield RMSc sight. Trijicon's RMRcc is longer, and requires an adapter plate which also necessarily raises the mounting surface in order to mount an RMRcc.
RMRcc has its own footprint. Gone are the two lug holes in front, these are replaced by two larger diameter threaded posts (bosses) through which the sight to mount/plate screws are installed. The sight to mount/plate screws are also significantly strengthened, though with the OPF-G, RMRcc design that holds the sight immobile on the plate, the larger diameter and stronger screws aren't as important, we always welcome screws that are less likely to strip.
With the OPF-G43x/48, RMRcc, we didn't merely raise the mounting surface to provide a platform for the RMRcc. As RMRcc is longer than the G43X/48 MOS cut, the sight overhangs on the slide. When installed, the bottom of RMRcc (with Trijicon provided sealing plate installed) is almost flush with the top of the slide so the sight is as low as possible. We positioned the RMRcc towards the center of the plate as much as feasible, this is done to reduce the amount of unsupported overhang on the RMRcc's sealing plate in front. RMRcc has a rubber gasket around its battery compartment to keep water and moisture at bay, which pushes the sealing plate downward. This isn't an issue if the plate is of the same length as the RMRcc, but with an overhang, it creates a slight gap between the gasket and the sealing plate. OPF-G43x/48, RMRcc's design eliminates the gap/opening between the sight and sealer plate, to the point of emulating a plate that's as long as the sight itself. To wit, if the plate is as long as the RMRcc, it will make the installed height of RMRcc even taller, which is the very reason we chose to let the sight overhang.
Front over hang. We did not want the sealer plate, and the sight to make contact with the top of the slide, the sealing plate to top of the slide gap is around 0.005. There isn't any gap between the RMRcc and the sealer plate.