Directly connecting NVMe 2.5 in. U.2 SSD to PCIe 4-lane slot, NVMe 2.5 in. U.2 SSD PCIe adapter consists of PCIe 4X add-on-card with 68-pin SFF-8639 female connector. SFF-8643 PCIe 4X adapter connects 2.5 in. NVMe U.2 (SFF-8639) SSD to PCIe 4-lane slot in system via SFF-8643 cable. Installed into M2 PCIe SSD socket to turn it into SFF-8643 connector, M2 SFF-8643 converter enables NVMe 2.5 in. U.2 SSD to be attached to system PCI BUS via M2 PCIe SSD socket using SFF-8639 to SFF-8643 cable.