Features Highly Integrated Chip: Optical fiber visual fault locator pen using a highly integrated chip, integrating power management, modulation, switching control. Multiple Electrostatic : Visual fault locator through fiber optic coupling, optical power packaging, nanotechnology, multiple electrostatic , with optical port device. Laser Head Stability: Pen fiber optic fault detector, easy to penetrate, long distance fiber, laser head stability, good penetration effect. Standard 2.5mm Interface: Visual fault locator with strong red light, standard 2.5mm interface, non slip handle, comfortable in hand, compact size, easy to put into the pocket, does not take up space, convenient travel. Aluminum Alloy Material: Fiber optic visual fault locator excellent aluminum alloy material, strong performance, corrosion resistance, wear resistance and drop resistance. Spec: Item Type: Fiber Optic Visual Fault Locator Material: Aluminum alloy Battery: 1.5V AA batteries x 2 (shipped without batteries) Use: Fiber optic communication detection Working Wavelength: 630nm-670nm How to Use: 1. Unscrew the tail cover and put in the battery 2. Unscrew the dust cover 3. Connect the fiber optic cable packing list: 1 x Fiber Optic Visual Fault Locator 1 x Instruction Manual 1 x Portable Storage Bag 1 x Lanyard Package List 1 x Fiber Optic Visual Fault Locator 1 x Instruction Manual 1 x Portable Storage Bag 1 x Lanyard