Abstract: A defense device, mounted on a wrist watch and made part of it, has a gas chamber underneath the wrist watch. The chamber, containing pressurized repellant gas, is locked to the watch with an interlocking ring between the watch and the gas chamber. The gas can be released by a user by pushing a trigger end of a pin to actuate the release of the gas at the other end, where a nozzle discharges the gas sideways in a wide spray impinging on an incoming attacker. The invention is formed to blend inconspicuously with the design of the watch, so as to prevent the incoming attacker from knowing of the device. A user of the device may pretend to read the time, while in reality releasing the repellant gas from the side of the hand to the incoming attacker. The interlocking ring has an aperture at the top to accommodate a wrist watch, and an aperture at the bottom to accept a matching gas chamber and lock it into position, ready for firing.