The Triplett 3388 Fox & Hound HotWire Live Circuit Tracing Kit traces wires for 120 VAC and 220 VAC circuits. It consists of the HotWire Fox Transmitter and the HotWire Hound Receiver. The HotWire Fox applies a Radio Frequency (RF) tracing signal to the wire to be traced, and this RF signal propagates down the wire radiating the signal along the length of the wire. The HotWire Hound senses the location and strength of this RF signal, and in doing so, identifies the path of the wire to the user.

The HotWire can also trace other common wires, whether powered or unpowered. For example, it can trace telephone and cable TV wires, LAN cables, security system wires, and many others. The HotWire Fox, in addition to generating RF signals, also generates Audio Frequency (AF) signals which can be sensed with the Triplett Hound, Hound 2, Hound 3, or Hound Jr. In some cases, tracing a wire using the AF signal is advantageous.

The HotWire Fox also includes a very useful feature called TrueTrace. In situations where it can be used, it provides positive identification of the wire being traced. This is especially useful in instances where "crosstalk" makes identifying the wire being traced, called the "target" wire, difficult.

The HotWire's RF signal can be sensed through most building materials (wood, plaster, drywall, concrete, brick, etc.) and can often be sensed through metal conduit (because the conduit is often poorly grounded, as far as RF is concerned). The HotWire can even trace shallowly buried underground wires, like those commonly used for "Invisible Fences", cable television, telephone, or low voltage landscape lighting.