The ST120+ Socket Tester With A Gfci Test Button and Beeper From Fluke Is The Perfect Tester For Electricians and Electrical Inspectors, Home Inspectors and Technicians Who Need to Verify The Correct Wiring Of Outlets. The Bright, Easy to See Leds Let You Know If An Outlet Is Miswired and The Integrated Gfci Test Button Gives You Peace Of Mind By Allowing You to Verify The Proper Operation Of Gfci Equipped Outlets.The Addition Of A Switchable Beeper Makes The ST120+ Even More Capable. In Addition to Provid