Pen-design Visual Fault Locator (VFL), Pen-size and light weight, specially designed for field personnel who need an efficient and economical tool for fiber tracing, fiber routing and continuity checking in optical networks. It finds breakpoints, poor connections, bending or cracking in fiber optic cables: and it can find faults in an OTDR dead zone and is used for end-to-end visual fiber identifications. It is suitable for both single mode and multimode fiber.