[Accurate Identification] This visual fault locator accurately detects and locates fiber breaks, poor connections, bends, or cracks. It operates in both CW and pulse mode. The VFL emits 650 nanometer red light for fiber tracking and positioning. Breaks or malfunctions refract the light within the fiber.[Function] The fiber tester offers multiple functions including constant output power, low battery warning, long battery life, and long-distance detection. Enables efficient fiber routing and continuity checks with a bright light indicating the faulty area.[Wide Application] Universal 2.5mm connector compatible with LC, ST, and other fiber optic cables, suitable for both round and square connectors. Tests single-mode and multi-mode cables. Applicable to integrated wiring systems and fiber optic engineering, CATV engineering, optical network maintenance, photoelectric communication, optical measurement, drive engineering, and optical equipment production and research.[Detection Distance] This visual fault locator features 30mW strong output power with constant output, capable of detecting up to 20-30 kilometers in fiber optic cable. High-efficiency power supply circuit ensures stable performance in both continuous wave and pulse modes.[Practical Design] Comes with batteryno additional purchase required. Compact and lightweight pen-style design with carrying case and hanging rope for easy portability. Features a stainless steel tip and aluminum body for durability against impact and dust. Grounded shell design helps prevent electrostatic discharge damage.Color: Black Material: Metal + Plastic Size: 17.5 x 2.6 x 2.6 cm Package Contents: 1 x 30mW VFL Red Light Pen 1 x Carrying Case 1 x Hanging Rope 1 x AA Battery Note: Lighting and display differences may cause slight color variations between the image and the actual item. Measurement allows an error of +/- 1-3 cm.