A simple arrangement of neon lights which visually indicates correct wiring reverse polarity open ground neutral or hot wire hot and ground reversed hot wire on neutral terminal and hot terminal unwired. Simply plug into a single phase 125 volt 2 pole 3 wire outlet and combination of lit/unlit lamps will immediately indicate condition of circuit. Instructions and symbol identification are printed on durable polyester labels permanently attached to tester. Can test other 2 pole 3 wire phase 125 volt outlets with proper use of correct adapter. MFG# HBL5200 UPC# 783585808314