OPF-G43x/48, RMRcc is designed for and only compatible with GLOCK G43x and 48, and Trijicon's RMRcc. It will not work with other GLOCK models, and other red dot sights. G43x and 48 MOS slides are designed for direct mounting of the Shield RMSc sight. 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. Trijicon's RMR is longer and wider, and requires an adapter plate which also necessarily raises the mounting surface in order to mount an RMRcc.