I don’t know, but I can tell you that the ones I received recently were different than the locks I had on hand and have bought previously. The end.

Just judging by looking at the pictures, it appears that the outside profile was done with the same punch and die on all of the pieces. One of the locks shown had the hole and tab pierced from the opposite side of the blank. The appearance of the pierced tab on the two on the left is different from the two on the right and the finish on the surface of the material is definitely different. Can not be sure without a detail inspection but it does appear that all came from the same tool so I am back to a difference in raw material because of the difference in the surface appearance. In addition, there could be some wear on the punch and die or a difference in tensile strength of material that resulted in a difference in the tab opening which appears to be the most critical dimension for function.

Yes there are knock offs on the market
The same guy TRYED to copy my FORMULA ONE.
I bought a Qt from him. Took it to my chemist. My chemist said .The knock off has way to many fillers in it.

I figured that must be what is going on. What a shame. Folks best buy these things straight from www.snareone.com if they want to make sure they get the real macoy.