The BESANTEK BSTCBF01 Circuit Breaker Identifier is a fuse and fault finder which comprises of two parts; the receiver and the transmitter. The transmitter draws a current from the main supply circuit to which it is connected and requires no batteries. The Signal Current from the Tx is about 10kHz, which is then searched (sniffed) by the receiver to detect the fuse, circuit breaker or the faulty circuit. The amplitude of the received signal is shown on a bar-graph using LEDs. The more LEDs that are lit up, the stronger the signal.