The Asus ZenBook Pro 14 UX450FDX Laptop Supports Single and Dual Drive Configurations. (One 2.5" Solid State Drive or Hard Drive and/or One M.2 NGFF (2280) Solid State Drive) Note: If the 2.5" Drive was not installed from Asus, you will need the 2.5" Drive caddy and connector board for installation. (The M.2 slot supports SATA and PCIe NVMe Solid State Drives)