Abstract: An alarm device comprises an RFID circuit that is configured to store identification information and is coupled to an antenna designed to receive and to emit, from and to an RFID reader, signals at the frequency of the RFID reader, and a switch coupled to the antenna and able to be activated by a user, enabling the antenna to be matched to the frequency of the RFID reader. The alarm device comprises the RFID circuit, the antenna and the switch designed to be incorporated into an object worn by a user, and enable the alarm to be activated discreetly.