Fangrui Product Details And High Quality! This Inst Ent Is Designed To Identify And Trace Wires Or Cables Without Damaging The Insulation. You Can Also Use It To Check Short Circuit And Loacting Open Circuit And So On. There Are A Sender And A Receiver Included In The Inst Ent. Tracing Of Wires Is Made Possible Even Inside Bundles, Conduits, Behind Panels, Under Carpets, Upholstery, Etc Easy To Use: Simply Connect The Mitter In Series With The Circuit Or Wire Under Test, (i.e.: In Place Of A Blown Fuse, Across A Connector,in Series With An Open Wire, A Light Bulb Socket, Etc.), And Scanning The Circuit/wire With The Tracers Flexible Probe To Find The Trouble Spot 6-42 V Ready: For Use In The Generation Of Vehicles With Mixed Or Single 42 Volt Systems Operates On Dc Voltages From 6 To 42 Volts Internally Protected Against Power Surges And Overloads 7inch Flexible Probe Allows Reaching Wires In Congested Places Mitter And Receiver Leds Show Open Or Short Circuit Conditions Adjustable Sensitivity For All Tracing Situations No Wir