Gardner Bender Circuit Breaker Finder locates AC circuits quickly and easily, making electrical work more efficient and hassle-. To use, simply plug the transmitter into a wall outlet on the circuit you want to identify, then run the receiver over the circuit breakers or fuses in your load center. The receiver will beep and flash when it detects the correct circuit, allowing you to find it without interrupting power. This device does not interfere with sensitive electronic equipment, ensuring safe operation. The receiver is powered by one 9V battery (not included) and is UL listed for safety and reliability. Its voltage range is 80V to 140V, and it comes packaged in a convenient clamshell. Model Number: CS550A