A Visual Fault Locator (VFL) is an essential, low-cost fiber optic testing tool that uses a bright red laser (\(650\text{nm}\) wavelength) to identify fiber breaks, bends, cracks, or faulty connectors. By injecting light into the cable, it allows technicians to visually pinpoint damage, verify continuity, and trace fibers over distances typically up to \(15\text{km}\)—\(50\text{km}\).