GAPP

Are they legal in NJ? I know the regulations regarding the 5 "offensive" characteristics but I was under the impression that AKs are on the banned list and illegal unless they are significantly different in form (Ive heard the single stack mag version is ok). A double stack AK was offered to me for sale and I want to make sure its legal. Im not sure of the manufacturer so any imput would be appreciated regarding what versions/models/manufacturers are legal and illegal. Thank you in advance.