The Wilcom FR2 Optical Fault Locator is a rugged, lightweight, hand-held , easy-to-use optical fault locator for multimode and singlemode applications. Using OTDR ( Optical Time Domain Reflectometer ) technology, the FR2 is designed to pinpoint faults in optical cable, that can be over 20 kilometers away, with amazing accuracy. The FR2 operates at the industry standard wavelength of 1310nm, and can display the distance to the fault in meters or feet.