92FS mags

I picked up some 15rd 92FS mags, the usual stampings is PB CAL 9 PARA MADE IN USA (instead of Italy). There's another stamping on the other side ASS'Y 9346413-65490.
What kind of mags are these?

US military issue markings. Beretta-made M9 mags are preferred to contract-made mags manufactured by Checkmate, as the non-Beretta mags have a rough phosphate finish on the inside surfaces that has been reported to cause or contribute to jamming in very sandy/dusty conditions. Use in confidence.

Ah I see. thanks. I also picked up a couple used Checkmate, complete with sands :D All these mags seem to have metal follower, unlike my regular mags that came with the gun.