Fiber optic adapters (also called couplers) are designed to connect two fiber optic cables together. Most commonly, they provide for interconnection of cables having similar connectors in order to facilitate passage through an enclosure wall or to extend cable length. Products incorporating standard. L-com stocks a wide range of fiber optic couplers and adapters. Fiber optic's advantages over copper cabling are well known immunity to EMI and RFI, low attenuation over long distances, high bandwidth capacity, smaller size and lower weight.