... without any damage by detecting the optical signals being transmitted through them. Brief IntroductionST820B Optical fiber identifier is an essential ... multi adapter, easy replace-test bare fiber, tight tube optical fiber, optical fiber jumper-identify CW and modulated light 270HZ, 1KHZ, ... , 2PCS)5. Continuous working time: more than 4 hours6. Insert loss (1550nm): Φ250μm: 1.0dB, Φ900μm:0. 5dB, ...