OPF-G, RMR (Optics Platform, Glock, for RMR) is a Glock MOS Adapter Set 01 and Set 02 compatible plate for mounting Trijicon RMR or SRO on Glock Gen 4 and Gen 5 slides, G17, G19, G34, G35, G41 (width 25mm/1 inch.) and G40 that uses Set 02. Glock's OEM MOS plate's width matches that of the slide, but OPF-G, RMR is already wider to fully support the RMR, thus it is compatible with all MOS equipped Glock slides. We like the Glock MOS concept, even if we find the factory MOS adapter plates could use some help. Standards, commonality, availability of parts are all good things. Heretofore, users have had to send in their slides to be milled to accept mini red dot Mfg: Forward Controls Design