190 CBI and 191 CBI have the same shape but different Speciﬁcations. 190 CBI is an easy tool to ﬁnd the circuit breaker or fuse supplying electrical power to an outlet or lighting ﬁxture. Just plug the transmitter into the outlet. Use the receiver to scan the circuit breaker panel box. An audible tone will be clearly heard when the right circuit breaker is scanned. It is not necessary to shut off power to ﬁnd the right circuit breaker or fuse. 190 CBI is an ideal tool for both automated ofﬁce environments where disruption of power is not practical, as well as in residential applications. The plug of transmitter is changeable.The plug of transmitter could be changed for customers' requirement from different countries. Quickly identiﬁes and locates 110 ~ 125 VAC circuit breakers and fuses. It is not necessary to interrupt power. Audible tone generated when matching breaker is located. It is an easy way to identify location of circuit breaker on the circuit breaker panel box which is connected to a speciﬁc outlet.