The StarTech.com Advanced RJ45 LAN Cable tester allows a single person to test several long cables faster and more efficiently than ever before. The tester uses remote loop-back plugs that each have their own unique ID number that the tester can identify. If several cables need to be tested, the user simply puts a loop-back plug on the end of each cable run and goes to the other end to test and identify each one. The tester provides a basic continuity test with a pin-map that will identify wiring errors, allowing them to be quickly corrected. It also identifies several common pinnings and displays the applications for each. The LANTESTPRO requires a separate 9V battery that is not included to operate.