Fire arm equipped with an enabling system

A fire arm equipped with an enabling system, whereby the fire arm contains a device which can prevent any firing, whereas the enabling system contains a transmitter/receiver mounted on the fire arm, a unit to be carried by the shooter containing means to send back a signal transmitted by the transmitting part of the above-mentioned transmitter/receiver to the receiving part of this transmitter/receiver, and a monitoring device to monitor the signal received by said receiving part and to control the device which can prevent any firing, whereby the latter actually prevents the firing if the monitoring device does not recognize said signal as that of an authorized shooter, in which the transmitter/receiver is a transmitter/receiver of matter waves, and in that the enabling system contains a timer which can measure the length of time between the transmission of a signal by the transmitting part of the transmitter/receiver and its reception by the receiving part of this transmitter/receiver, and a device to calculate the distance covered by this signal on the basis of the measured time, whereby the monitoring device only makes it possible to fire when it has recognized the signal and when on top of that the above-mentioned distance is inferior to a certain limit.