The QSFP-40G-ESR4-ST is an MSA compatible fiber transceiver module that has been designed, programmed and tested to work with MSA 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 300 m (984 ft). This QSFP+ fiber module is hot-swappable, making upgrades and replacements seamless by minimizing network disruptions. StarTech.com offers a wide variety of QSFP+ modules and direct-attach QSFP+ cables, providing the convenience and reliability you need to ensure dependable network performance.