Amplifier Probe, Battery: (1) 9 V Battery (Included), Battery Life: 50 HR Typical (Alkaline, 540 MILAMP-HR), Probe Tip Resistance : 1000 OHM Min, Input Impedance: 5.7 MOHM, Voltage Gain: 37 DB, Dimensions: 9.2 IN X 1.7 IN X 1.2 IN, Weight: 5 OZ (Including Battery), Designed To Identify And Trace Wires Or Cables Within A Group Without Damaging The Insulation