Suitable for Patch Cords with RJ11/RJ12/RJ45 & BNC connector, Tester with Master & Rmote unit, Suitable for old (BNC) and new (RJ45) patch cords, Various LEDs for status:, Loop-Back: localization of laid network cables, Continuity: of network or communication cables, Open: disconnected single wires, Shorts: short circuited single wires, Miss-Wire: Identification of non conform wire assigment, Powered by 1x 9 Volt block battery (not included)