An RFID unit includes an RFID unit A and an RFID unit B that are separable on a break line, where the RFID unit A includes an IC chip portion A that stores an UUID and an antenna portion A, and the RFID unit B includes an IC chip portion B that stores an UUID and an antenna portion B. Before the RFID unit is separated into the RFID unit A and RFID unit B, either the RFID unit A or RFID Unit B transmits a first signal including the UUID. After the separation, at least either the RFID unit A or RFID unit B transmits a second signal, different from the first signal, including the UUID.