StarTech Gigabit Fiber 1000Base-SX SFP Transceiver Module, Cisco GLC-SX-MMD Compatible, MM LC, 550m (GLCSXMMDST)100% Cisco Compatible. Guaranteed. The GLCSXMMDST is a Cisco GLC SX MMD compatible fiber transceiver module that has been designed, programmed and tested to work with Cisco brand compatible switches and routers. It delivers dependable 1 GbE connectivity over fiber cable, for 1000BASE SX compliant networks, with a maximum distance of up to 550 m (1804 ft). This SFP module is hot swappable making upgrades and replacements seamless by minimizing network