100% new tester, with LED lights and micro-power supply interface.Can test Gigabit less than or equal to AC 220V power supply POE pair line Keep your running smoothly by testing your cables to uncover problematic shorts, disconnect wires, crossing pairs and other wiring mishaps. Use for testing your homemade Ethernet patch cables to make sure they are in working order prior to connecting to your devices.Tests RJ45 cables, RJ11 telephone cables and cables. Easy to read LED display indicates problems.Hand-held for portability. Requires one 9-volt battery (not included). Battery is advised to change if any weak light appears.Or through the micro-port power work. Remote Tester: -4-5-6-7-8-G (RJ45) -4-5-6 -------- (RJ12) -2-3-3 -------------- (RJ11) Following are abnormal connections: 1.If one cable, for example cable No.3 is disconnect circuited, the two No 3 li-ghts of the main tester and remote tester will not turn on. 2.If several cables are not connected, several lights will not turn on -ectively.if less than two cables are connected, none of the light is on. 3.If two ends of a cable is disordered, for example NO.2 and No.4 than. Displays on: Main Tester: -4-5-6-7-8-G Remote Tester: -4-5-6-7-8-G 4. of two cables are short circuited, neither of the corresponding major is on of the remote tester while main tester remains unchanged.if three cables, including three, are short circuited, none of the corre-sponding lights is on. 5.If test patch panels or wall plate outets, two cables which can match each (eg 110P4 and Rj45) will be connected to the tester. colour: blue Material: ABS Size: 100x95x25mm Package Contents: 1 x cable tester 1 x Chinese and English manual Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.