A duplex fiber optic connector assembly enables mating the fibers of a first multifiber cable with like fibers of a second cable or cables with maximum axial alignment of the respective fiber paris. An interconnect member receives cable terminating connectors in opposite sides thereof. Each connector carries the fibers of a respective cable in individual ferrules, each ferrule having limited floating mount within the respective connector. The mating pairs of ferrules are received in opposite ends of receptor members each of which has an axially profiled bore adapted to receive the respective ferrules and a profiled outer surface which allows movement about the geometric center of the receptor so as to axially align the bores of the ferrules received therein. Connectors at each end of a predetermined length of fiber optic cable provide a fiber optic extension cord, analogous to the well-known electrical extension cord, for convenient and efficient interconnection between optical signal-using equipments. Small interconnect members receive the connectors of such fiber optic extension cords to allow even wider-ranging interconnections. Wall boxes containing such interconnect members, connected to permanently installed fiber optic cables conveying optical signals from a central optical signal source, allow a user to readily access optical signals by "plugging-in" a connector therein.