i got this glock magazine from a buddy but it is a high cap mag that is made out of steel. i cant seem to find out any thing about it on the net, gun broker sell a couple of them. I think the mag is made for the glock 18 fully auto but i am not for sure. some people say not to use that mag on glock because it can mess up the plastic on the gun. true or false?? Please help Thanks THis is the brand NOS USA MAGAZINE GLOCK STEEL MAG