Gardner Bender GRT-3500 Outlet Receptacle Tester & Circuit Analyzer, Indicates 5 Wiring Errors, Easy Read Chart, Comfort Grip, 120 VAC Indicating lamps reveal 5 common wiring errors: open ground, open neutral, open hot, hot/ground reverse, hot/neutral reverse Compact unit with comfort grips Dual status chart for multiple position viewing Integrated neon lenses Tests standard outlets and extension cords