The OFI-3 Optical Fiber Identifier is a low cost, portable instrument designed to detect optical signals without disrupting traffic. During maintenance, installations, rerouting or restorations, it抯 often necessary to isolate a specific fiber. By simply clamping the OFI-3 onto a fiber, the OFI will indicate if there is a signal, a Modulated Signal, or traffic and show signal direction. The OFI-3 is recommended for both 0.25/0.9 mm bare fiber and 3mm jacketed fiber. When testing coated fibers, the slim design of the OFI-3 allows easier access to a splice tray where the amount of work space is limited. The clamping trigger is designed to fit the natural motion of the operator抯 hand. A highly impact molded plastic case makes the OFI-3 suitable for use outside plant or in the central office.