Foto4easy Telephone RJ45 RJ11 RJ12 Cat5e Cat6 USB UTP Network Lan Cable Tester Test Tool Test correspondingly double-twisted cables 1, 2, 3, 4, 5, 6, 7, 8 and Ground Capable to judge wrong connection, short circuit and open circuit Cable Tester for RJ12, RJ11, RJ45, Cat 5e, Cat 5, 10/100 Base-T, AT&T 258 A, TIA-568A/568B. etc 9 LED lights to indicated wiring connection on both remote and master unit Verifying Cable continuity, open, short and cross wire pair up to 1000ft with remote kit