KCI Mags
I have some for my G19. they work......... they are not Glock quality.
At first they seem to be the same except for the markings. Little things are there to be found. Kind of hard to pinpoint, but as I use them more, I can see that they are not the same.
IE, Pittsburgh tools from Harbor freight or Snap-On tools. (I think you know what I mean.......)
To quote an old tire commercial, "You can feel it when you drive"
The more I handled them, the more I felt the difference in their function. I had a couple of times where the ammo did not feed up the mag as expected when unloading a mag. They seemed to always fire when in the gun, but to carry.............NO WAY.
They may make the grade as a training mag only and labeled as such for snap caps and doing malfunction drills.