Feature: 1. MAIN PURPOSE: The visual fault detector is specially designed for the design and maintenance of optical fiber, to locate the fracture and defect on the optical cable. 2. LESS INTERFERENCE: Non contact connection, lossless optical fiber and the end face of the transmitter, the output power is not affected by the voltage fluctuation. 3. WORKING RANGE: The output wavelength of the optical fiber detector is 650nm+ 10nm, the output distance is 15KM, with less interference, the detector is stable and reliable. 4. PORTABLE DESIGN: The visual fault detector is a portable design, small and compact, with stable output power, suitable for indoor and outdoor use. 5. ALUMINUM SHELL: The optical fiber test pen shell is made of aluminum, which is lightweight, corrosion resistant and abrasion resistant, ensuring long term use. Specification: Item Type: Visual Fault Detector Model: HT 15 Material: Aluminum Universal Interface: 2.5mm (FC SC ST) Output Wavelength: 650nm+ 10nm Output Optical Power: >15mw Optical Fiber Adapter: Universal Connector Output Distance: 15km Operating Temperature: 0 60 celsius Storage Temperature: 20 70 celsius Battery Type: 2 x 1.5V AA Battery (not included). Package List: 1 x Visual Fault Detector1 x Pen Bag1 x Lanyard 1 x User Manual Note: Do not aim at the eyes.