The MT-7028 lets you easily locate and verify the cable status and
  troubleshoot wiring for continuity, shorts,
  opens and crossover on RJ45 Lan cable Cat 5、5e、6、7 (UTP/STP)、
  RJ11/12 Telephone cable Cat. 3 (2/4/6 pin) & normal solid/Stranded wire
  by alligator clips patch cord. Ideal for all installation and maintenance fields
  of telecommunication, networking, datacom, Audio/Video, cable TV,
  and all weather cabling, etc.

  The tone and probe kit let you easily tracking wire directly in connection with
  live telecommunication equipment and router

  Cable Mapping & status Indication up to 300M

•  Fast/Slow scan function for choosing
•  Display the result of pin to pin cable mapping
•  Display cable status and troubleshoot wiring for continuity, shorts, opens and crossover.

  Non Contact Voltage detection

  Tests voltage from 90 ~ 1000V, special design to make sure the power is off
  before testing for circuit protection

  Polarity indication

  Identify the telephone line polarity easily

  Energy saving

  Automatically powers off after 1 hour of no operation