Building on the success of the original BarrelBlok, Blok Safety Systems has introduced a magazine insert called MagBlok. MagBlok is a cartridge-shaped device that is inserted into the top of an empty magazine. The specially engineered tool allows two important mechanical functions to be performed when it is properly inserted. First, MagBlok prevents the magazine follower from engaging the slide stop lever. This prevents "slide lock" when training with an empty magazine. Second, a ramp channel on the top of MagBlok allows for the full back-and-forth movement of the slide. The updated product is now called the BarrelBlok Pro series of products. It includes one BarrelBlok safety device and three MagBlok inserts. MagBlok is not sold separately.