Rosewill RTK-006 Network Cable Tester for RJ45 RJ11 RJ12 CAT5 CAT 6 UTP Network Lan Cable Ethernet Cable and Telephone Cable Cable tester for RJ45 Ethernet Lan Network cables, and RJ11 telephone cables. Correspondingly test double-twisted cables 1, 2, 3, 4, 5, 6, 7, 8 and ground. Keep your network running smoothly by testing wrong connection, short circuit and open circuit. 9 LED lights to indicate wiring connection on both remote and master unit. Easy read LED display which indicates problems. Detachable remote tester, test remote cable up to 1000ft. in length. Small and easy carried with smooth lines which is designed drop prevented and portable hand-held. Easily switch between slow automatic grade and manual grade. Auto scanning function for rapid testing