The FLS-140 is the easiest way to identify optical fibers from end to end and locate polished connector endfaces. An optical fiber cable fault locator is an essential diagnostic tool used in telecommunications and network maintenance to identify breaks, bends, splices, and other impairments in fiber optic cables. Break results and details are displayed on a large LCD screen. Compact and. AFL has a complete range of fast, easy-to-use tools that inspect and clean fiber endfaces. Using them consistently eliminates the #1 cause of network outages – dirty connectors.