Features: EASY AND ACCURATE IDENTIFICATION: It can easily and accurately detect and locate fiber breaks, bad connections, bends or cracks. The tester emits a 650nm bright light for fiber detection; breaks or faults in the fiber will interrupt the light. PRACTICAL DESIGN AND EXCELLENT FUNCTION: Small size and light weight, it is portable and easy for field test with multiple functions such as constant power output, low battery warning, long battery life and long-distance detection. WIDELY USED: The tester's 2.5mm universal connector is compatible with ST, SC, FC connectors in both circular and square shapes of various fiber optic cables. Suitable for both single-mode and multi-mode cables. LONG OUTPUT DISTANCE: This 30mW visual fault tester outputs strong red light up to 20-30 kilometers, with high-efficiency circuits enabling stable performance. PORTABLE: Pen-type design with pocket clip makes it portable. Easy to check fiber faults with visual fault finder. Durable, dust-proof design helps keep fiber connector clean. Specification: Optical output power: >30mW Output distance: 30km Output wavelength: 650nm Fiber optic adapter: Universal connector Operating temperature: 0~60°C Storage temperature: -20~70°C Battery type: 5 alkaline batteries (not included) Dimensions: 175 x 26 x 26mm Product weight: 173g Package included: 1 x Visual Fault Locator (batteries not included) 1 x Carry bag 1 x Neck strap