These are Revolver Supply Premium moon clips. They are chambered in both 9 MM and 38 Super.
We have tightened up the critical dimensions of our original part. They now hold the brass a bit more firmer.
They are 0.035" thick, made from high carbon steel and are heat treated and a Nickel plating finish is applied. They have been tested with Winchester, Remington, Federal and Starline brass.
The carbon steel design is useful if you have the moon clip holders that have magnets to hold the loaded moon clips.
The plating process will add 0.001" to 0.002" of thickness to each moon clip. So use these for a tighter fit than the blued 0.035" moon clips.