The IOCrest SI-PEX40110 allows you to install an M.2 NGFF PCIe SSD with a high or low profile PCI 3.0 x4 card to your System. 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.