The Triplett 3399 Fox & Hound Premium Tone and Probe Kit consists of a versatile Fox 2 Tone Generator (Toner) and a high performance Hound 3 Inductive Amplifier (Probe). The Fox 2 is a battery operated handheld multi-function Toner that generates multiple tones (Pulse or Warble), performs several basic telephone line tests (loop mA, line polarity, and ringing voltage), provides a visual and audible continuity test, and integrates Triplett's True Trace and TripLatch tests while providing overload protection up to 120 VAC. The Hound 3 is a battery operated handheld lightweight Probe, with a thumbwheel Sensitivity control and Signal Strength indicator LED. It improves on previous designs with built-in LED headlights to illuminate dark areas and reduce fluorescent light noise, a bandpass filter to suppress unwanted frequencies, an earphone jack for noisy or quiet work areas, and an easy access battery cover. The included convenient carrying case (with a belt loop attachment) provides ease of use and protective storage for the Fox 2 and Hound 3.

When used together, the Fox 2 and Hound 3 aid in identifying, locating, and tracing wires, cables, and other conductors. When the Fox 2 is used to apply a "tone" to a wire, the Hound 3 can usually locate the wire inside of, or behind electrically non-conductive surfaces (plastic, wood, drywall, etc.), up to 12 inches away. The Hound 3 does not have to contact a wire to identify it, meaning that no stripping is needed. The Fox and Hound tools can be used for numerous applications, including the telephone, electrical, security, sound reinforcement, video, automotive, and boating industries.