... tester with voice,can Test RJ45 and RJ11 network cables 2.Test correspondingly double-twisted cables 1, 2, 3, 4, 5, 6, 7, 8 and Ground 3 ... , 3, 4, 5, 6, 7, 8 and Ground5.Can judge wrong connection, short circuit adm open circuit6.Put cables into both main tester and remote tester ... . in length. 8.Power supply: DC 9V batteryUpdate Date:2011-3-30 1:12:31 telephone line tester with voice HOT!!!