The ST816B Visual Fault Locator is specially designed to allow quick and efficient maintenance of fibre optic networks and can be used for tracing and continuity checks allowing rapid identification of specific fibres. 25mm Universal Adapter Summary 650nm visual fault locator has the function of fiber identification and faults locator of SM or MM fiber, it is a helpful assistant to dead zone of OTDR, it is also a basic maintenance tool for fiber network, LAN, ATM fiber system and. The Senter ST816 pen-sized, visual, fault locator (VFL) is a robust, economy tool for checking the integrity of fibre-optic links. Used to identify break points in a fibre cable, or to check integrity of field-terminated connectors and splices, the VFL sends a visible, 650nm wavelength, red light. With more than 20 years of experience in the field of optical detection, Grandway has independently developed and produced various common optical testing instruments. like (OTDR, fusion splicer, PON tester, power meter, laser source, etc). The ST816B emits a bright 650nm light that will 'leak' through broken, cracked. ST816B Visual Fault Locator Fiber Optic Laser Pen 650nm Mini 10mW VFL provides precise fault detection in fiber optic networks. Ideal for CW or 2Hz modulation. comFiber optic test equipment for amplified or analogue transmission systems up to >+30 dBm.