The Commercial Electric OTG-102 Outlet Tester with GFCI is designed to provide a safe and reliable way of the most common wiring problems detection in standard and GFCI 3-wire receptacles. It can detect Open Ground- Open Neutral- Open Hot- Hot_Ground Reverse- Hot_Neutral Reverse- Correct Wiring. A light sequence on the tester helps locate the wiring condition in outlet according to the light result. Highlights Tester is designed to detect the most common wiring problems in standard and GFCI receptacles. Test range: 110_125 volts AC at 50_60Hz in a 3-wire outlet. Tester can perform the entire array of tests by simply plugging the device into the outlet. One-button design provides easy GFCI test. Easy to operate with light indicators. No battery required. Tester features CAT II 125V safety rating.