StarTech.com Dell EMC SFP-1G-BX40-U Compatible SFP Module - 1000BASE-BX-U - 1 GbE Gigabit Ethernet BiDi Fiber (SMF) - Dell EMC SFP-1G-BX40-U Compatible Transceiver - 1000BASE-BX WDM SFP+ (1 Gbps) - 1 Gigabit BiDi Module - 1310nmTx/1490nmRx Single Mode (SMF) - 40km (24.8mi) - LC Connector & DDM - Hot-Swappable / MSA Compliant - Lifetime Warranty