The Lenovo ThinkPad E15 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 5B40S72981 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 bracket with connector p/n 4XH0S69185 for installation. (The M.2 slot supports SATA and PCIe NVMe Solid State Drives)