GLCLXSMRGDST Compatible LC Single Mode Transceiver Module, Full Duplex. The GLCLXSMRGDST is a Cisco GLC-LX-SM-RGD compatible fiber transceiver module that has been designed, programmed and tested to work with Cisco® brand switches and routers. It delivers dependable 1 GbE connectivity over fiber cable, for 1000BASE-LX compliant networks, with a maximum distance of up to 10 km (6.2 mi).