Test AC/DC Voltage From 120 - 480 Volts, 50-60 Hz And DC Polarity. Dual Voltage Indication: Solenoid Vibration And Neon Bulb. Neon Bulb Indicates DC Polarity. Probes Lock Together For One Handed Testing Of Standard Outlets, Separate For Up To 4' Reach. Tests Outlets, Panels, Switches, Circuit Breakers And Light Fixtures. UL Listed.