Klein Tools 69149 Electrical Test Kit The MM300 multimeter measures AC/DC voltage, DC current and resistance and has a safety rating of CAT III 600V, Class 2, Double insulation The NCVT-1 has a bright green LED to indicate the tester is working; it changes to red and warning tones sound when voltage is detected NCVT-1 has a digitally-controlled ON/OFF power button and auto power-off feature to conserve and extend battery life Receptacle tester detects wiring configurations and indicates correct wiring, and identifies common wiring faults Identifies open ground, open hot, open neutral, hot/ground reversed; it does not indicate quality of ground, multiple hot wires, or a combination of defects