StarTech.com Dell EMC QSFP-40G-LR4 Compatible QSFP+ Module, 40GBASE-LR4, 40GbE Single Mode (SMF) Fiber SMF Optic Transceiver, 40GE Gigabit Ethernet QSFP+, LC Connector, 10km, 1311nm, DDM - Lifetime Warranty (QSFP40GLR4ES) - QSFP+ transceiver module (equivalent to: Dell EMC QSFP-40G-LR4) - 40GbE - 40GBase-LR4 - MPO single-mode - up to 10 km - 1311 nm