Features:• The amplifier probe is designed to identify and trace wires or cables within a group without damaging the insulation• Works with any tone generator to identify wires• Volume control for increased sensitivity and adjustable to suit work environment• Recessed On/Off button prevents battery drain• It can be power with only one 9V battery and the device has a long battery life (approx. 100 hours of use)• A plug receptacle is provided for use with a headset or headphone• Red and black test leads are provided, and it has a standard conductor modular cord and plug• A 3-position toggle switch controls the modes of operation plus a 3-colored LED is provided for the line polarity, continuity and voltage testing• A tone selector switch, located inside the test set is provided for choosing either a single solid tone or dual alternating tone (CAUTION: Do'nt connect to an Active AC circuit exceeding 24V in this mode)