High efficiency: Easily identifies fiber breakpoints, poor connections, bending, or cracking to locate the correct fiber for splicing or quickly finding a break. The 30mW fault locator emits a 650nm red light for fiber tracing, fiber routing, and continuity checking. Breaks or faults in the fiber refract the light, creating a visible glow around the faulty area. Functions: This fiber optic tester is ideal for field testing with multiple functions including constant output, multi-interface adaptation, low battery warning, long battery life, and long-distance detection. Powered by standard AA batteries for convenient use. Widely Used: 2.5mm universal connector designed to be compatible with ST, SC, FC, and LC interfaces, suitable for both circular and shaped fiber optic cables. Long Output Distance: The 30mW fault locator features a strong light source capable of outputting a visible red indicating light up to 20-30 kilometers. The high-efficiency circuit ensures stable performance. Crash-proof and Dust-proof Design: Features a stainless steel pen head and aluminum body to resist impact and dust. The grounded case design helps prevent ESD damage. Battery: Requires two 1.5V AA batteries (not included) Color: Green + Black Material: Aluminum alloy Package Contents: 1 x Fiber Identifier Note: Light and display differences may cause slight color variations compared to the actual item. Measurement error allowance: +/- 1-3 cm.