Farnell® UK offers fast quotes, same day dispatch, fast delivery, wide inventory, datasheets & technical support. WCFO designs and manufactures a full family of FC products including a full line of FC adapters. The FC Adapters are available in MM, SM and APC options and include D1 through D5 hybrid adapter versions. WCFO's FC adapters feature precision zirconia and phosphor bronze alignment sleeves and precise. A fiber optic adapter, sometimes also called a coupler, is a small device designed to terminate or link the fiber optic cables or fiber optic connectors between two fiber optic lines. It is commonly used when connecting fiber optic cables to equipment such as switches, routers, and transceivers.