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 5 to1000 VAC. Frequency 50 to 500 Hz. Measurement category CAT IV, 1000 V. Includes two 1.5 V AAA batteries.