Professional Network LAN Tester is made of high quality materials. This tester tests RJ45 and BNC network cables. Checks RJ-45 and BNC network cables. Checks up to four pairs of conductors for continuity and correct polarity is a portable enhanced network cable tester offering both RJ-45 and coaxial cable tests. Test of non-shielded double-twisted cables:If all the cables work,the lights will become green from No.1 & 2 to
No.7 & 8 sequently.LED diagnostic display Includes a remote display and shield ground test.