The invention relates to a system including individual identifier devices (1) which communicate using radio frequency and are associated with the objects (2) to be located or included in an inventory and at least one initialising device (3) for storing the values of the bar code (21) of the object (2) in the corresponding identifier device (1), using radio frequency transmitters in accordance with the IEEE 802.15.4 standard. The identifier devices (1) can also be located by transmission and reception antenna stations (4) distributed throughout the installation to be checked, such as a commercial centre or an airport. The identifier device (1) consists of a casing attachable to the object (2) or product with securing means (11) and containing the transmitter (12), a memory (13), a battery (14) and other elements. The initialising device (3) consists of a casing, the radio frequency transmitter (31), a micro controller (32), a bar code reader (33) and other elements.