The Cisco 30-1301-02 is a Cisco 1000BASE-SX SFP (Small Form-Factor Pluggable) transceiver module, also known by its part number GLC-SX-MM. This hot-swappable module converts electrical signals to optical signals for use with fiber optic cables, commonly employed in Gigabit Ethernet networks to link ports with the network. It features a duplex LC connector and operates with an 850nm optical wavelength, designed for multi-mode fiber and supporting distances up to 1800 feet (approximately 550 meters).