Gun concealed in a flashlight.
Unlike the Gun Flashlight, the original Flashlight Gun is capable of being used as both a flashlight and a gun - even simultaneously [Episode #70: "That Old Gang of Mine"].
Zach Smart with the 1995 model flashlight gun.
However, the nineties version, while appearing more muscular, evidently lacks this capability, functioning only as a gun [GS95 Episode #3: "Goodbye Ms. Chip"].