Built in white LED illumination light provides convenient work in dark areas. Detect AC voltage from 90 to 1000 VAC without metallic contact. Compact size with pocket clip easily fits into pocket or tool pouch. Red LED and audible alarm if voltage is present. Enter outer surface is non-conductive for safety; helps avoid high voltage shock. Powered by two 1.5V AAA batteries, not included. CAT IV 1000V safety rating. Great for Electricians, maintenance staff, service & safety personnel, and DIY/homeowners.