The Lenovo ThinkBook 15 IIL 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 5B40S21968 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 p/n 5B40S21967 and cable p/n 5C10S30015 for installation. (The M.2 slot supports PCIe NVMe Solid State Drives)