The Socket & See SOK36 Loop and RCD Socket Tester is an advanced check plug capable of performing a wide range of tests including finding socket wiring faults, earth loop impedance testing, and RCD testing. The tester has an audible and visual indication of wiring faults with ‘Fault Locate’ technology and can show whether the fault is on live, earth or neutral. The loop impedance test for earth quality indicates if an urgent check is required whilst there is also an operation check of RCDs.