Optics in the images are for reference only, they are not included.

VFC original slide (and outer barrel) which have been tapped for M4 for the Shield SMS footprint, incidentally the screws spacing allow for the installation of Leupold Deltapoint, Eotech EFLX provided you cut the bolts (M4) down to the relevant length and potentially head size depending on the model of the optic, but for Shield SMS (and clones), they will be compatible with M4 button heads. RMRs are totally different footprint fwiw. 

I have drilled and tapped these for action air IPSC to mimic a "production optics light G17" I used overseas for IPSC, which means they've gone through enough rounds for me to know that despite the thin material, the threads have been able to hold a lightweight optic like the SMS just fine. I've since bought a dedicated MOS steel slide for increased recoil which means these are no longer needed.