This SFP (mini-GBIC) transceiver module is designed for use with Cisco network equipment and is equivalent to Cisco part number GLC-SX-MMD. This transceiver is built to meet or exceed the specifications of the OEM and to comply with Multi-Source Agreement (MSA) standards. This product is 100% functionally tested, and compatibility is guaranteed. The transceiver is hot-swappable input/output device which allows a Gigabit Ethernet port to link with a fibre optic network. OEM specific configuration data is loaded on to the EEPROM of the transceiver at the factory, allowing this transceiver to initialise and perform identically to an OEM transceiver. This transceiver may be mixed and deployed with other OEM or third party transceivers and will deliver seamless network performance. A list of compatible network equipment is available on the Specs tab of this page.nn[B]Please Note:[/B] Installing Legrand transceivers does not void your network equipment warranty. Network equipment manufacturers all have guidelines stating that warranty support on their products will not be affected by installing a Legrand or any third party transceiver.