[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 efficient fiber tracing, fiber routing, and continuity checking. Breaks or faults in the fiber will refract the light, creating a visible glow around the affected area.[Functions] This fiber optic tester is ideal for field testing with multiple features including constant output power, multi-interface compatibility, low battery warning, long 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, and LC interfaces, both round and square shaped fiber optic cables.[Long Output Distance] The 30mW visual fault locator delivers strong output power, emitting a powerful red indicator light effective up to 20-30 kilometers. High-efficiency power supply circuit ensures stable performance.[Crash-proof and Dust-proof Pen Design] Features a stainless steel tip and aluminum body for durability against impact and dust. Grounded case design helps prevent ESD damage.Batteries: Two 1.5V AA batteries (not included) Type: A Color: Green + Black Material: Aluminum alloy Package Contents: 1 x Fiber identifier Note: Other items not included. Note: Lighting and display differences may cause slight color variations between the image and actual item. Measurement error allowance is +/- 1-3 cm.