Cables Unlimited Smartronix Superlooper TST-LOOP-006 Gigabit Loopback Tester Check cables for broken or shorted wires,Plug the Loopback Jack & Plug into any network Check wall jack to network switch connections Use the Smartronix Ethernet Analyzer and Loopback Jack and molded hybrid casing providing both male and female jacks Small, convenient, and economical for network technicians Color coded by network type for quick recognition