Professional telephone test set. Hi-z monitoring will not disrupt network traffic. High and low volume settings, polarity LED (light emitting diode), tone & pulse modes. ABN (Angled bed of nails) clips with rugged RJ45 and RJ11 plugs. Terminates twisted pair category cable into wall jacks and patch panels for phone and data communications. Includes both 110 and 66-style, long life metal-injection-molded blades. Comfortable double-molded tool body fits hand. Wire hook and spudger accessory tools pull out with easy-to-use thumb studs. Blades available separately. Powered by (1) CR2032 battery.