This device is inexpensive way to quickly identify pinched fibers, a breakpoint, poor connections, bending or bad splices. A red laser injects visible light into a optical fiber. When the red light shows through at a break, it is easy for a tech to spot the problem. It is important to note that that a microbends do not allow as much light to escape through the fiber jacket therefore it may be necessary to darken the area to better see the damaged area.