The first version the magazine was all one piece, so those were all prohib. There was a version that came out with a regular magazine tube (5 round) and a 3 round extension that was removable. In my case, I just built my own. Bought the security version with the 18.5" barrel, and added scattergun technologies ghost ring sights, a +2 (or +3 I can't remember) extension from S & J (properly plugged of course), a pic rail scope base, oversized safety, tactical charging handle (all from Simon at S & J) and a 5 round side saddle. Not factory, but it works, and I like the Scattergun Technologies sights better.