SFPEX is the original manufacturer of Cisco SFP GLC-SX-MMD - Cisco 1000BASE-SX SFP transceiver module for MMF, 850-nm wavelength, 550m, extended operating temperature range and DOM support, dual LC/PC connector . We have ready stock for GLC-SX-MMD and can ship it out in two business days. We guarantee the GLC-SX-MMD transceiver module to work in your system and all of our GLC-SX-MMD transceiver modules come with a lifetime warranty. The GLC-SX-MMD is a Class 1 laser product. It fully complies with the multi-sourcing agreement (MSA) which enables it to work in all MSA compliant platforms. The GLC-SX-MMD must be operatred within the specified temperature and voltage limits. The optical ports of the module shall be terminated with an optical connector or with a dust plug.