The QSFP-40G-SR4-S-ST is a Cisco QSFP-40G-SR4-S compatible fiber transceiver module that has been designed, programmed & tested to work with Cisco brand switches & routers. It delivers dependable 40 Gb E connectivity over fiber cable, for 40 G Base-SR4 compliant networks, with a maximum distance of up to 100 m (328 ft). This QSFP+ fiber module is hot-swappable, making upgrades & replacements seamless by minimizing network disruptions. Star Tech.com offers a wide variety of SFP modules & direct-attach SFP cables, providing the convenience & reliability you need to ensure dependable network performance.