Here's a few more pictures. I agree that the flash hider looks similar to the PM90 it definitely isn't. I had a chance for better pictures and made a few comparisons for size. The Chinese National Match, this unidentified flash hider, a German slant brake, and a (Polytech?) muzzle nut. The inside of the flash hider is small. I don't have a mic to fit down in there but the mouth of a 7.62 round will barely fit. Would be the tightest tolerance I've ever seen on an AK muzzle device so any chance this is a 5.56/5.45 size flash hider?