The Dell Vostro 3501 Laptop Supports Single and Dual Drive Configurations. (One 2.5" Solid State Drive or Hard Drive and/or One M.2 NGFF (2280) or (2230) Solid State Drive) Note: If the 2.5" Drive was not installed from Dell, you will need the 2.5" Drive caddy p/n xxxxx and cable p/n xxxxx for installation. If the M.2 Drive was not installed from Dell, you will need the M.2 thermal bracket p/n HTHJM for installation. (The M.2 slot supports SATA and PCIe NVMe Solid State Drives)