Pen size, fits into pocket or tool pouch. Detects power and voltage without touching the bare conductor. For use on power wiring plus lighting, thermostats and other low voltage circuits. Use to detect voltage in outlets, fixtures, wires and cables. Finds breaks in wires. Identifies hot and neutral conductors. Low battery indication. Voltage detection: AC 5-1000 volts. Frequency: 50-500Hz. Measurement category CAT IV, 1000 volts. Includes two 1.5 volt AAA batteries.