FO86306 Fiber Optic Identifier is an essential installation and maintenance instrument. By inserting the fiber into its adapter head, the fiber optic identifier can identify SM optical fibers without any damage by detecting the optical signals being transmitted through them so as to avoid the opening of the fiber at the splice point for identification and thus avoids the interruption of the service. In the presence of traffic, the intermittently audible tone is activated. This FO86306 fiber optic identifier also allows relative core power display and identification of the 270Hz,1kHz and 2kHz frequencies. When they are used to detect the frequency, the continuously audible tone is activated.