PVD= sand resistant 15 round mags. They ship with the M9A1s. Im away from home right now,but ill post a photo of mine later.
Frankly, ive prefered the balance of the 15 round mags to the 18 round MecGars or 17 round "Italian" mags.The latter two mags seem to alter the balance of the gun beyond my comfort for carry purposes. Odd how two or three rounds can do that,but here we are.
-Forgot to note, the 17 round Beretta mags are a pain to load compared to the 15 rounders or the MecGar(think PX4 Storm spring resistance).The price for more rounds is mandatory use of a magazine loader during extended sessions.