Product overview: Fluke ST120 GFCI Socket Tester
Fluke ST120 Socket Tester with GFCI

The Fluke ST120 GFCI Socket Tester checks that each wire in the outlet is properly connected to the building's electrical system. Via the bright LEDs and included chart, you can quickly and easily verify the wiring of an outlet. Able to identify several common wiring errors, including reversed phase and neutral wires and an open ground, the ST120 will give you confidence on your next job.

One-button GFCI tests
The included GFCI test button on the ST120 Socket Tester allows you to also test the operation of GFCI outlets. With a single push, the ST120 can verify the operation of your GFCI equipped outlet. If the GFCI trips as expected, perfect, you can move on. If not, it’s time to take a closer look.

Fast visual identification of all 6 wiring conditions
The ST120 has three bright, easy-to-see LED indicators. This lets you see, at a glance, one of six wiring scenarios:

Correct installation
Open ground
Open neutral
Open hot
Hot/neutral reversed
Hot/ground reversed