The copy says K footprint, so it looks like two widths with that same footprint. I'm assuming one for the thin guns like 43x mos, shield plus, 365 etc...and one for those running the k footprint on 19 sized or regular width slides.
Printable View
Screw hole spacing looks the same to me. The one on the right has more material outside of the screw holes than the one on the left but the amount of material on the inside of the two holes looks the same. How many people had full-size slides cut for the thinner Shield footprint?
Looks like the EVO next to the 509T, based on size...
Disregard, I'm a dumbass. 509T doesn't mount that way. So an enclosed 507 (evo) and enclosed 507K (evo). I don't doubt I'll buy one, try it, find the lighting adjustments not workable for me on a compact carry pistol, and pass it along at a loss, like everything else I've tried so far.