The QSFP40GER4ES is a Cisco QSFP-40G-SR4-S compatible fiber transceiver module that has been designed, programmed and tested to work with Cisco brand switches and routers. It delivers dependable 40 GbE connectivity over fiber cable, for 40GBase-SR4 compliant networks, with a maximum distance of up to 40 km (24.8 mi). This QSFP+ fiber module is hot-swappable, making upgrades and replacements seamless by minimizing network disruptions. StarTech.com offers a wide variety of SFP modules and direct-attach SFP cables, providing the convenience and reliability you need to ensure dependable network performance.