Quickly and easily checks network cables. Cable Tester for RJ45, RJ11 Cat5, Cat6, 10/100 Base-T, AT&T 258 A, TIA-568A/568B etc. Checks open and short terminals, straight through or crossover wiring types. Ideal for I.T enthusiasts who wish to make their own network cables. Test correspondingly double-twisted cables 1, 2, 3, 4, 5, 6, 7, 8 and Ground. 9 LED lights to indicated wiring connection on both remote and master unit Grounding Test.