The Monoprice LAN Cable Solution is one of the easiest to use and most complete multifunction cable testers available.The tester can test the integrity of RJ45, RJ11/12, F-type Coax, and BNC Coax cables for shorts, open conductors, crossed wires, and cable length. The 16 x 4 character LCD display shows either Pass or Fail on any cable test, and if Failed, the specific wires that failed and the type of failure.The Loopback testing mode can test any RJ type cable (11/12/45) with each end connected directly to the tester. This can test for Open, Short, Crossed, or Split conditions for each conductor. It also identifies whether the RJ cable is shielded or unshielded. Additionally, it can show the distance along the cable at which an Open occurs using the built-in Time Delay Reflectometer (TDR), allowing you to easily locate the point of failure. Cable length can be tested out to 350 meters.Both the Length and Tone modes are tested without a terminator or direct connection to the other end of the cable. The length mode shows the total length of the cable, or the length to any existing cable break. In Tone mode the tester sends a tone down the cable, which can be sensed using an Amplifier Probe (not included). This can be used identify cables within a bundle or as an alternate method of locating cable breaks.A built-in memory module allows you to store 8 results each for LAN and TEL modes, plus 4 results each for Coax and Length modes. The tester has an automatic power-off feature to save battery life, which kicks in after 5 minutes of nonuse in all modes except TONE mode, and after 30 minutes in TONE mode.WARNING!!! Do not test live circuits as it could cause damage to the tester unit or personal injury.*** 30-day easy returns. No restocking fee. Free lifetime technical support. 1 year warranty. ***