CS 400 CS 400 universal bidirectional receiver (SRL400 and KLCD WIRELESS), triple frequency (433.27 MHz, 433.92 MHz, 434.57 MHz) anticollision; radio own protocol in rolling-code 112bit, auto-learning programming, antenna, power supply, 12V, buzzer and LEDs for real time status of the transmitter and the bell plus antiopening Tamper.