This 3-Piece Tool Set includes Cat. No. NCVT2P Dual Range Non-Contact Voltage Tester, 12 - 1000-Volt AC, Cat. No. ET60 AC/DC Voltage Tester, and Cat. No. RT210 GFCI Receptacle Tester. The NCVT2P is a non-contact voltage tester that detects 12 to 1000V AC and indicates the presence of voltage in cables, cords, circuit breakers, light fixtures, switches, outlets and wires as well as AC voltage in doorbells, thermostats, low voltage lighting and irrigation systems. The ET60 is a solid-state, low impedance, electronic voltage tester. It measures AC/DC voltages up to 600V. The ET60 does NOT require batteries; it is powered by the applied voltage. The GFCI Outlet tester is designed to detect the most common wiring problems in standard and GFCI receptacles. A convenient chart on the tester helps determine wiring condition in outlet, based on LED lights results. Conditions indicated: open ground, reverse polarity, open hot, open neutral, hot/ground reversed.