Main Functions:1. Check and find the needed cables among so many cables in one time.2. Continuity test wiremap for Lan cables.3. Diagnose the breakage, open, short, cross.4. Visible indication: pin-to-pin cable map for individual cable (not by pairs).5. Transmitter with RJ11 connector and pair of alligator clips.6. Low Voltage alarm function.7. Earphone permits use in noisy environments.8. LED light assists use in dark corners.