High efficiency: Easy identification of fiber breakpoints, poor connections, bending, or cracking for locating the correct fiber to splice or quickly finding faults. The 30mW visual fault locator emits a 650nm bright red light for fiber tracing, fiber routing, and continuity checking. Breaks or faults in the fiber will refract the light, creating a visible glow at the fault point. Functions: This fiber optic tester is ideal for field testing with features including constant output power, multi-interface compatibility, low battery warning, extended battery life, and long-distance detection. Super bright output powered by convenient AA batteries. Widely used: 2.5mm universal connector designed to be compatible with ST, SC, FC, and LC interfaces, supporting both round and square shaped fiber optic cables. Long output distance: The 30mW visual fault locator delivers strong red light output capable of reaching distances up to 20-30 km. High-efficiency power circuit ensures stable operation. Crash-proof and dust-proof pen-style design: Features a stainless steel tip and aluminum body to resist impact and dust. 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 optic visual fault locator Note: Other items not included. Slight color variation may occur due to lighting and screen display differences. Measurement error allowance: +/- 1-3 cm.