The RADIUM 1, 2 and 4 buttons key chain style remotes are operating at 433,92 MHz. It has been designed for the control of automatic closing systems and anti-burglar systems, thanks to its very high security coding system (KeeLoq® Hopping code). The code sent by the transmitter changes at each activation, avoiding any scanning and copying risk. A special algorithm allows to keep synchronized transmitter and receiver. The transmitter can be equipped with passive tag.