Optimal Shop Multifunctional RJ45 RJ11 RJ12 CAT5 UTP Network LAN Cable Tester Networking Tool Can test correspondingly double-twisted cables 1, 2, 3, 4, 5, 6, 7, 8andG, meanwhile, Can judge wrong connection, short circuit and open circuit. Can tests RJ 11and RJ45 Test of double-twisted cables: Switch on the power. (S is slow automatic grade, Mis manual.) Put cables into both main tester and remote tester. The lights of the main tester will turn on sequently form 1 to G.