Features Fiber Optic Tester: Specially designed for optical cables and lines maintenance, the VFL pen could locate defects on cables, visually search for fiber breaks. Easy for Operation: Conforms to ergonomic design for easier turning on and off, the VFL can also be used as a lighting for working and operation in the dark. Better Application: A must have tool for fiber optic engineering construction, fiber optic network maintenance, and fiber optic device production and research. Wide Compatibility: Comes with a 2.5mm universal interface for FC SC ST, the visual fault locator can be quickly charged by power bank, computer, adapter and more. Convenient Carrying: Light in weight and compact in size as well, the fiber light tester is very convenient to carry with you for outdoor works. Specification: Item Type: Visual Fault Locator Test Distance: 15KM Working Current: ≤ 150mA Battery Life: >3.5h Output Level: 3 adjustable level output.  Output Wavelength: 650nm Interface: 2.5mm Universal Interface Power: 2 x AAA battery, shipped without battery.  Storage Temperature: -40~+85 ℃ Working Temperature: -20~+60 ℃, no condensing.  Package List: 1 x Visual Fault Locator 1 x Ceramic Sleeve 1 x User Manual Package List 1 x Visual Fault Locator 1 x Ceramic Sleeve 1 x User Manual