The Triplett ET330 Non-Contact Voltage Detector can easily check for the presence of AC Voltage before working on a circuit. It has dual AC voltage ranges (24 to 1000V and 90 to 1000V) with high sensitivity that allows it to detect low voltage AC wiring commonly found in doorbell circuits, thermostats, control circuits, and video surveillance camera power. It features audible and visual alarms, a built-in flashlight, CAT IV 1000V safety category and meets cETLus and CE. Includes (2) AAA batteries. 1-year warranty.