SFP-SX-D ZyXEL COMPATIBLE Transceiver Module - 1000Base-SX SFP, Gigabit, Multimode, 850nm 550m, Dual LC Connector, with DDMI &nbsp; ZyXEL Compatible 1000Base-SX SFP, Gigabit, Multimode, 850nm 550m, Dual LC Connector, with DDMI