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 make it portable and suitable for field testing. Features include 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, and FC connectors on both round and square fiber optic cables. Works with both single-mode and multi-mode cables. LONG OUTPUT DISTANCE: This 30mW visual fault locator outputs a strong red light visible up to 20-30 kilometers. High-efficiency circuits ensure stable performance. PORTABLE: Pen-type design with pocket clip for portability. Easy to use for checking fiber faults with visual indication. Durable and dust-proof design helps keep the fiber connector clean. Specification: Optical output power: >30mW Detection distance: 30km Output wavelength: 650nm Fiber optic adapter: Universal 2.5mm connector Operating temperature: 0°C to 60°C Storage temperature: -20°C to 70°C Battery type: 5 AAA alkaline batteries (not included) Size: 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