Detects voltage in outlets, light fixings, circuit breakers, wires and cables or finds breaks in wires. LED and audible alarms. Voltage detection 70-1000V AC frequency 50/60Hz. Measurement category CAT III, 1000V per UL3111-1 CAT IV, 600V per IEC61010-1. Overall length 150mm. Requires 2 x AAA batteries.