Abstract: A firearm safety device comprising a pair of combination lock type dials mounted concentrically and rotatably on the gun casing. The dial in contact with the casing has an aperture spaced a selected radial distance from the center. The other dial has a pocket spaced the same distance so that they may be aligned together. A plunger is mounted in the casing at the same distance and is spring biased outwardly and axially movable. The inner end of the plunger is extensible into a moving part of the firing mechanism. Aligning the pocket and aperture with the plunger allows it to spring out of engagement with the moving part, therefore releasing the safety, or unlocking the firearm. Sloping grooves adjacent the pocket and aperture depress the plunger when the dials are rotated.