5mW 650nm Red Laser Fiber Optic Cable Visual Fault Locator Tester (2 x AA) Universally connector for test different ST,SC,FC interfaces Test for both single-mode and multi-mode cables with optional 2.5mm fiber optic(Standard) Operates in both CW(Continuous wave) and pulse mode Dust-proof design keep fiber connectors clean Connector: universal(2.5mm ferrule)F601B 2.5mm