VisiFault emits a bright beam of red light easily visible from a distance. Perform simple end-to-end continuity checks. Visual fault locator cable continuity tester locates fibers, finds faults, verifies continuity and polarity. In today's fast-paced workplace maximizing productivity is essential. A VFL emits a visible red laser (typically 650 nm) that travels along the fiber core and leaks out at points of excessive loss, fiber breaks, or microbends. This guide covers the actual workflow: connecting safely, choosing continuous vs modulated mode, what different glow patterns mean, and the field. The state, throughput, and identification of an optical fiber can be easily checked with fiber testers by coupling highly visible laser light into the optical fiber.