StarTech.com Dell EMC QSFP-40G-ESR4 Compatible QSFP+ Module, 40GBASE-SR4, 40GbE Multimode Fiber MMF Optic Transceiver, 40GE Gigabit Ethernet QSFP+, MPO Connector, 400m, 850nm, DDM, 40Gbps - Lifetime Warranty (QSFP40GESR4E) - QSFP+ transceiver module (equivalent to: Dell EMC QSFP-40G-ESR4) - 40GbE - 40GBASE-SR4 - MPO multi-mode - up to 400 m - 850 nm