The Tactical Thumb Safety are used for concealed carry and tactical use. They must have a narrow profile thumb safety to keep them from being accidentally disengaged and snagging on clothing when drawn yet once out of the holster they must be quickly manipulated without failure. The extended lever is serrated to provide ample control under stress conditions without the interference that is inherent with a wide safety. This is without a doubt one of the finest concealed combat safeties on the market. Fits: A thru O