I picked up one, and tried it out, nonplussed.
Big gaps, poor finish (the two pieces are plastic welded together and don't appear to have passed a finisher--very shoddy).
If you are looking for something to fit as tightly and beautifully as the extended mag on a XD sub compact, keep on looking.
C'mon Glock, come out with an o-fish-al extended mag with integrated spacer already! These aftermarket parts are garbage.
Anyone else had better luck than I am having with this Pro Mag spacer? I seem to have missed the Pro Mag Spacer Shim Kit
Give a man a fish and feed him for a day, teach a man to fish and you'll never see him on the weekends