This single-port 40GbE adapter is built around the XL710 controller and is compatible with XL710-QDA1 deployments. The QSFP+ cage supports 40GBASE-SR4/LR4 optical modules and 40GBASE-CR4 DAC; it can also operate as 4×10GbE via QSFP+ breakout (modules and splitter cables are sold separately). With PCIe 3.0 x8 bandwidth, SR-IOV virtualization, RSS/MSI-X, jumbo frames up to 9K, and VXLAN/GENEVE/NVGRE tunnel offloads, it delivers low-latency throughput for modern data centers. It is widely used in VMware ESXi, Hyper-V, KVM/Proxmox, TrueNAS, and pfSense environments for 40G uplinks, storage (iSCSI/NFS), and high-speed VM traffic. Dual brackets (full-height & low-profile) help it fit 1U/2U chassis and compact cases; ensure a free PCIe 3.0 x8 (or x16) slot and adequate airflow. Note that this is a QSFP+ interface (not RJ45); choose proper optics/DAC. Also referred to as a PCI network adapter by users (PCIe interface).