... Fiber 20Km 1310nm SC/FC connector 220V or 48V RS485 Fiber Modem, Dual Fiber Mini Rack Fiber Optical MultiplexerSPD-RS485-D-20 ... -131SRS485 Fiber Modem, Single Mode, Dual Fiber, 20Km, 1310nm, SC/FC connector 220V or ... -D-20-131S: Single Mode, Dual Fiber, 20km, 1310nm, SC/FC connector 220V or 48V, Mini rack RS485 Fiber Modem. We ...