Easy, Safe, Quick and Accurate. Non-contact from 70 V AC to 600 V AC. Contact test from 70 V AC to 250 V AC. DC voltage test: 0-250 V DC. Polarity test: 1.5 V DC to 36 V DC. Continuity check: 0 - 80 M ohms. Checks operating condition of ionizer. Detects microwave leakage: ≥5mw/cm2 . LR41 batteries included.