Specification:Probe length: 7 "flexibleReceiver size: 38.5 x 4 x 2.3 cm (height x width x depth, approximate)Transmitter size: 6.5 x 5.6 x 2.1 cm (height x width x depth, approximate value)Dc voltage: 6 to 42VPower supply: 2x9V battery (6F22) (Not included)How to use the probe?The probe of the Receiver is built of coiled steel and may be bent as needed, in order to reach wires in congested or difficult areas. Depending on the circuit characteristic and sensitivity settings, the probe will pick up the signal from the wire in a range of positions. However,for the best possible range the Receiver's probe tip (black ) should be positioned perpendicular (at 90o) to the wire being traced and either above or below it. This instrument is designed to identify and trace wires or cables without damaging the insulation. You can also use it in checking for short circuit and locating open circuit and so on.There are a Sender and a Receiver included in the instrument.Features: Tracing of wires is made possible even inside bundles, conduits, behind panels, under carpets, upholstery, etc Easy to use: simply connect the transmitter 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 42 V Ready: for use in the new 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 7" flexible probe allows reaching wires in congested places Transmitter and Receiver LEDs show open or short circuit conditions Adjustable sensitivity for all tracing situations No wire piercing required, non-contact technology!