Fiber optic visual fault locator adopts 650nm laser diode as a light emitting device,the output power can be up to 1mw-30mw. It’s applied to single-mode or multi-mode fiber measurements.It uses 2pcs of 1.5v AA battery for power supply and FC adapter  as an output interface.In the meantime, you can use SC / ST adapter and do not need to configure the conversion interface furthermore, it can optionally connect all frequently-used joint.HY-20 fiber optic visual fault locator is an ideal tool to test various types of optic fiber patch cord, ribbon, bundle fiber optic pigtail and maintain a variety of fiber optic lines for you.