The 500XP Pair Tracing Tone Probe helps technicians install, service, and maintain voice, datacom, and video networks faster, safer, and easier than ever. This easy to use tone probe features real-time, proportional signal processing, acAlert™ hazardous AC voltage warning, advanced Nautilus® ergonomics, and a headset connection with improved signal fidelity. Patented – Patent #6946850, 8754269