The Lenovo ThinkPad E595 Laptop Supports Single and Dual Drive Configurations. (One 2.5" Solid State Drive or Hard Drive and/or One M.2 NGFF (2280) or (2242) Solid State Drive) Note: The M.2 (2242) Drive uses a adapter bracket p/n 01LW427 to accommodate for the larger M.2 (2280) slot. If the 2.5" Drive was not installed from Lenovo, you will need the 2.5" Drive caddy and cable for installation. (The M.2 slot supports PCIe NVMe Solid State Drives)