GUNDAY RMR Mount Base w/ Sight Kit for Marui & WE Glock GBB Series

The rear sight mount does correctly fit a RMR footprint optic, but it does not attach to the slide very well. The "camming" piece that sticks into the slide is very shallow and not shaped correctly to the TM G18C slide (which is kind of like a trapezoid from the side). I believe TM G17s also have this trapezoid profile, so this will not work for that either.

You can attempt to work around this by tightening down the screw through the BBU into the sight mount, but the screw is very thin, it's smaller than M3, possibly M2. Even then, the recoil will most likely cause the sight mount to begin walking itself loose. It's not a matter of losing 0, it will quite literally be skewed off to the side.

The design is great, the plate is very thin and the raised front and rear sights do provide co-witness options, however, since it cannot be mounted, it is entirely useless