It's Easy To Analyze Circuits Test for a variety of conditions using Del City's GFI Receptacle Tester and Circuit Analyzer by plugging the tester into any circuit protected by a ground fault receptacle (110-125 V AC) and pressing a button to overload the circuit. This unit can test 7 conditions including: ground fault interruption, open ground, open neutral, open hot, hot/ground reverse, hot/neutral reverse and correct wiring. Red and yellow lights provide a visual indication of circuit status or specify which wire is defective. The tester trips GFCI between 6-9mA and is CSA and UL listed.