Use To Test For "Hot" Wires Before You Begin Electrical WorkTests: Outlets, Panels, Light Fixtures, Switches, Electrical Cords And MoreBeeps And Flashes To Indicate The Presence Of AC Voltage From 50V To 600VFully Insulated Probe Tip Eliminates The Risk Of Contacting Live Electrical WiresBuilt In Safe Test Indicates Tester And Batteries Are Working ProperlyCompact Design With Pocket clip For PortabilityTester Is C/ETL/UL Listed And Offers CAT III RatingBattery Type: 1-AAA (Not Included)