[Accurate identification] This visual fault locator can and accurately detect and locate fiber breaks, poor connections, bends or cracks. It can run in CW or pulse mode. VFL will emit 650 nanometer red light for fiber tracking and positioning. Breaks or malfunctions will refract the light in the fiber.[ function] The fiber tester has multiple functions including constant output power, low battery warning, long battery life, and long-distance detection. Efficient fiber routing and continuity check produce a bright light in the faulty area.[Wide application] Universal 2.5mm designed for LC, ST, , can interfere with the round and square of different fiber optic cables, and test single-mode and multi-mode cables. Applicable to: integrated wiring system and optical fiber engineering; CATV engineering optical network maintenance; photoelectric communication; optical measurement drive engineering; optical equipment production and research.[Detection distance] This visual fault locator has 30mW strong output power, constant output power, strong red light 20-30 kilometers in the fiber optic cable, high-efficiency power supply circuit provides stable power, continuous wave and pulse mode.[Practical design] With battery, no additional purchase is required. Small and light, pen-shaped design with bag, easy to carry, easy to check fiber faults, visual fault location, the design uses stainless steel head and aluminum body to prevent collision and dust, and the shell ground design effectively prevents electrostatic discharge damage.colour: blackMaterial: metal + plasticSize: 17.5x2.6x2.6cmPackage Contents:1 x 30mw VFL Red Light Pen1 x Carrying case1 x Hanging rope1 x AA-size BatteriesOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.