The SFP1GBX40DES is a Dell EMC SFP-1G-BX40-D compatible downstream fiber SFP transceiver which pairs with StarTech.com's SFP1GBX40UES. They are designed, programmed and tested to work with 1000Base-BX40 compatible Dell EMC switches and routers. The SFP transceiver module supports a maximum distance of up to 40 km (24.8 mi) and delivers dependable 1 GbE connectivity over fiber cabling. Technical Specifications: Wavelength: 1490nmTx/1310nmRx Maximum Data Transfer Rate: 1000 Mbps (1 Gbps) Type: Single Mode Fiber Connection Type: LC Connector Maximum Transfer Distance: 40 km (24.8 mi) MTBF: 3,713,222 hours Power Consumption: < 1.6W DDM: Yes This SFP fiber module is hot-swappable, making upgrades and replacements seamless by minimizing network disruptions. StarTech.com SFPs All StarTech.com SFP & SFP+ transceiver modules are backed by a lifetime warranty and free lifetime multilingual technical support. 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.