Unfortunately the old pre-ban cz and mec-gar 15 round mags can almost always hold 16 rounds. So even though marked 15, I would think they would be illegal in NJ, unless there is a state pre-ban exception. NY got rid of the pre-ban exception, and soon 10 round mags (or lower capacity) will be the only ones legal in the state. And you can only load 7 unless you're at the range!