This is the description wrote on the add. I'm thing about buying some.
Kahn Glock M22 .40 S&W 15rd
[DS Pallet] KAHN M22 Magazines are manufactured in Korea. Used by several multi national Law Enforcement and Military contracts they are built to current production FML (Full Metal Lined) specifications that are often referred to as "Drop Free". KAHN M22 magazines hold the full capacity 15 Rounds. Mag has no markings on floorplate or mag body.
__________________
To educate a man in mind and not in morals is to educate a menace to society.
They are half the price of factory drop free glock mags. I dont have any first hand expirience with them myself but from other peoples experiences, some bad ones and some good ones.
Personally Ive never had a single malfunction with a factory glock mag. Id just stick with what I know works and pay the extra $8-10 dollars for Glock factory ones.
Good to keep in mind that most malfunctions in a mag fed weapon are mag related. Range mags are sneaky, they'll try to get in with your carry mags! Don't trust'em. I was trained to give a mag three strikes. Mark it each time there's a malfunction, and when it has three strikes fix it with a sledge hammer and toss it in the trash.