Built around the Ethernet Controller X540, this dual-port 10GBASE-T adapter delivers reliable 10 GbE over standard RJ45 copper. Each port supports CAT6A up to 100 m (CAT6 up to 55 m) and auto-negotiates down to 1 Gb/100 Mb to fit mixed networks. With PCIe 2.0 x8 and an integrated MAC+PHY design, it offers SR-IOV, VMDq, RSS, TSO/LRO, VLAN 802.1Q, Jumbo Frames, checksum/flow-control, DCB, and PXE/iSCSI boot for virtualization, storage, and data-center workloads. Full-height and low-profile brackets are included for 1U/2U racks or desktops to simplify chassis fit and cooling paths. Widely supported across Windows Server, Linux, FreeBSD, VMware ESXi, and popular NAS/firewall platforms (pfSense, TrueNAS, unRAID). Also referred to as a PCI network adapter by users (PCIe interface). Use CAT6A for 10 Gb up to 100 m and confirm RJ45 copper is appropriate for your switch/NAS to ensure standards compliance.