Check the listing for details. Klein Tools RT210 GFCI Outlet / Receptacle Tester. Condition: Used. Listed at 20.00 USD. Klein Tools RT210 GFCI Outlet Tester Klein Tools Receptacle Testers are 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. GFCI Tester detects the most common wiring problems in standard and GFCI receptacles Works on GFCI outlets and confirms operation of the ground fault protective device Built to withstand a 6.6-foot (2m) drop Operating temp: 32-Degree to 140-Degree Fahrenheit (0-Degree to 40-Degree Celsius) Nominal Voltage: 110/125V AC at 50/60Hz in 3-wire outlet Track Page Views WithAuctiva's Counter