Descriptions: It is specially designed for field personnel who need an efficient and economoical tool for tracing,fiber routing andcontinuity checking in an optical netwerk during and after installation. The pocket size tool send s a visible red laser light thouth fiber optic calbes.Breaks or faults in the fiber will refract the light,creating a bright glow around the faulty area.The universal connector can be used for all the most commonly used fiber interfaces. What is in box ? 1 x 20mW Visual Fault Locator