Ordered some Trijicon silencer height night sights for the G40. Plan on buying a Trijicon RMR for it at the end of the month. However, never one for patience, I realized I had a Burris Fastfire floating around. Glock mentions a lot of mini red dots, but does not mention the Fast Fire at all. Nonetheless, it looked like it would fit on the 1st mounting plate, so I went for it. Had to use the shorter screws that came with the plate pack to mount the Fast Fire, but otherwise, it went on without a hitch.