The RFID transponder (or Tag RFID) is part of the active transponders. It is particularly recommended for mass event (running, mountain bike, cycling) when it is difficult to retrieve transponders after the event.
The Tag RFID can be glued directly on the bib or on the bike. On the human body, metal or carbon, the Tag RFID must be removed as far as possible to ensure reliable detection.
RFID transponders are used for detection only, it is not possible to have accurate timing.