If they are advertised as Vektor magazines (probably out of D.S. Arms in 'Shotgun News'), they were made for the Vektor SP1 and Z88 pistols (you can see them at
http://www.vektorusa.com) used by South African police and the military forces. The Z88 is a near exact clone of the Beretta 92, and the SP1 frame is made from the same blanks as the Z88, though it has a different safety.
From what I had read in a Peter Kokalis article about 9 years ago, the magazines are of better quality than Beretta mags, and in an American Rifleman article (Dope Bag) two years reviewing the SP1, the writers said the the SP1 would accept and function with aftermarket Beretta 92 mags. I would think that the converse of this is true (Berettas accepting SP1/Z88 mags), and I bought 4 of them when they were more than 30 dollars. If D.S. Arms still has them, I might buy 2 more.
Overall they look like Beretta mags, and the condition that mine were in was excellent or better (I think they were refinished/refurbished, and had seen little use beforehand), and they seem to be a little heavier than the the factory Beretta magazines. they also have thicker magazine bases that will not fit in the factory carry case that Berettas come in. Hope this info helps.