FYI for NJ Residents I have the G 21SF with the Picatinny rail option and the ambi mag release. Needless to say the ambi mag release jammed on me then fell into pieces. I brought it to my gun store where I purchased and they sent it off to Glock for me for repair. Glock replaced the frame with the standard 21SF frame, which came with a new serial #. I actually had to obtain a new handgun permit to get my gun which I already bought and paid for back. Good thing I was prepared and had the permit ahead of time in anticipation of this. The gun store originally told me I wouldn't need a new permit, but they were wrong, which I figured. So, If you live in NJ and are having a defective handgun replaced with another, be prepared to get a new permit no matter what the guys at the gun store tell you. BTW, if you cant get a new handgun permit for whatever reason, you cant get your gun that you paid $600 (or whatever price) for back, basically you are **** out of luck. Thanks again NJ.