The Faithfull Socket Polarity Tester tests sockets quickly and easily. It can be used to determine whether socket wiring is correct or incorrect. Used in conjunction with the coding table provided, the 3 combined lamps indicate the state of the socket's wiring condition. The compact and durable design is easy to operate and read. Just plug into a socket for automatic detection. Specification: Socket Type: UK 240V 3-Pin Nominal Voltage: 240V Frequency Range: 50~60Hz Operating Temperature: 0°C to 40°C Dimensions: 71 x 62 x 62mm Weight: approx. 63g