The Fiber Break Tester from Parts4pc is a pocket sized tool that sends a visible red laser light though fiber optic cables. 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. Connector: Universal (2.5mm ferrule) Wavelength: 63520nm @25C Output Power: <5mW Spectral Width: <10nm Transmission: Continuous or 3Hz pulsed Range: Visibility up to 3km Power: 2 AAA 1.5V Alkaline Batteries