I have gotten both fake primos and fake sust from a supplier I had while living in France. The primos I knew were bogus by three ways. One the label peeled off like a sticker. Two the edges of the label were square not rounded. Three the stripes on the top of the amp looked like they were painted on rather than machine applied, Imperfect lines, and the blue dots were not aligned with eachother.!!! If you have two of the three symptoms they are bogus, bogus, bogus. Guy that ripped me got a good old fashioned American ass wooping....If they are bogus I recommend you do the same.