Prevent electrical shock with this simple tool to located dangerous defective grounds. This handheld device helps you determine the presence or absence of 50-1000 Volts AC in insulated wires, wall receptacles, fuses, junction boxes, and voltage carrying electrical systems. The bright, red glow indicates AC voltage. Features: Non-contact detection of 50-1000 VAC. Includes 2 replaceable AAA alkaline batteries. Senses voltage without metallic contact. Outstanding safety instrument.