Features: 1. The circuit breaker finder can automatically adjust sensitivity and find the target circuit breaker or fuse quickly. 2. The socket tester can test whether triangle socket connection is correct and 3 indicator lights can show you the socket condition. 3. With flashlight, convenient to use in the dark environment. 4. Support low battery warning. 5. Suitable for power grid rebuilding and engineering acceptance in office, home, factory, etc. Specification: : MASTECH Model: MS5902 Working Voltage: AC 220V Plug Type: UK plug Material: ABS Color: Black and Green Receiver Power Supply: 1 x 9V Battery ( Not included ) Receiver Size: 20 x 3.8 x 5cm or 7.9 x 1.5 x 2.0in Socket Tester: 6.3 x 7 x 5.5cm or 2.5 x 2.8 x 2.2in Packet Weight: Approx. 298g or 10.5oz Package list: 1 x Socket Tester with Transmitter 1 x Circuit Breaker Finder with Receiver Note: When the yellow LED is on, please replace the battery in time. .