The Uni-T UT681L is a portable and user-friendly cable connection tester designed for quickly checking the continuity and wiring of Ethernet (RJ45) and telephone (RJ11) cables.
1: It can identify common cable faults such as open circuits, short circuits, and crossover wiring. 
2: Featuring a simple single-button operation and LED indicators for displaying test results, it's a convenient tool for network technicians and DIY enthusiasts to troubleshoot cable connectivity issues.
3: The tester consists of a main unit and a detachable remote unit, allowing for testing of installed cables. It's powered by a 9V battery and often includes an auto power-off feature to conserve battery life.