The Dell Vostro 5501 Laptop Supports Single and Dual Drive Configurations. (Two M.2 NGFF (2280) or (2230) Solid State Drives) Note: Both of the M.2 slots support M.2 (2280) and (2230) Drives by moving the drive mounting bracket to accommodate the form factor. If adding a M.2 Drive. M.2 slot 1 (SSD1) uses M.2 mounting bracket p/n PXNWV for Installation and M.2 Slot 2 (SSD2) uses M.2 mounting bracket p/n KYMC9 for installation. (Both M.2 slots support SATA and PCIe NVMe Solid State Drives)