The expansion card lets you take full advantage of the fast performance and compact size of PCIe M.2 internal solid-state drives. The adapter connects directly to your computer motherboard to support an M.2 PCIe-based SSD (NVMe or AHCI) through ultra-fast x4 PCIe. The adapter is compatible with PCIe 3.0 motherboards and is also backward compatible with PCIe 2.0 and PCIe 1.0. With the M.2 PCIe based drive in place, the adapter gives your computer a significant speed boost. It is designed to work only with 'M' key M.2 PCIe SSD. Not compatible with a 'B' key M.2 PCIe x2 SSD or 'B' key M.2 SATA SSD.