The AR-15 Patriot Mag Release is made specifically to make your AR-15 compliant with the new 2017 law! If you aren’t looking to register your AR-15 then you NEED this to make it compliant. This is for the AR-15 platform only (.223 / 5.56). This kit locks your magazine into your AR-15 and requires you to extend the rear takedown pin, lift the upper receiver, press the magazine release button, and then remove the magazine. The Patriot Mag Release Kit is installed in addition to a standard AR-15 lower parts kit.