Features 1、DIRECTION IDENTIFICATION: Accurately identify the direction of the optical fiber. When there is a signal from the optical fiber, the left and right direction lights display the signal direction. The left direction light comes on, indicating that the light source is from right to left. 2、WITH ALARM: Fiber identifier effectively identifies traffic direction and frequency tones (270Hz, 1KHz, 2KHz) with audible warnings. 3、10KM MEASUREMENT DISTANCE: Built in VFL red light source can measure a distance of about 10 kilometers. 4、ABS MATERIAL: Made of premium ABS material, this optical fiber detector is wear resistant and scratch resistant for long service life. 5、EASY CARRYING: Comes with a small size and a light weight as well, this optical fiber tester can be easily carried around for convenient use. Specification Item Type: Optical Fiber Identifier Material: ABS Battery: Polymer lithium battery 3.7V 650mAh (shipped with built in battery) Application: Fiber optic identification Basic Parameters: Wavelength Range: 800 to 1700nm Signal Recognition Type: CW, 270Hz ± 5%, 1kHz ± 5%, 2kHz ± 5% Detector Type: Dia. Approx. 1mm / 0.04in InGaAs 2 pcs Adapted Fiber Type: Universal dia. 0.25, dia. 0.9 (for bare fibers), dia. 2.0, dia. 3.0 (for tail fiber) Signal Direction: LED indicator light for left and right direction indication Optical Power Reading Range: -50dBm to +26dBm Display Resolution Linear Display: 0.1%. Logarithmic Display: 0.01dBm Optical Power Meter Wavelength Range: 850 to 1650nm Use Distance of the Red Light Source: Greater than Approx. 10000m / 32808.4ft Working Temperature: -10 to +60 ℃ Storage Temperature: -25 to +70 ℃ Package List 1 x Optical Fiber Identifier 1 x Manual 1 x USB Cable 1 x Storage Box