The Lenovo ThinkBook K4-IAP Laptop Supports Single and Dual Drive Configurations. (One M.2 NGFF (2280) or (2242) Solid State Drive and/or One M.2 NGFF (2242) Solid State Drive) Note: There are two M.2 slots on the system board and both slots support M.2 2280 and M.2 2242 Drives. M.2 slot-1 (SSD1) supports PCIe Generation 4.0 x4 speeds and slot-2 (SSD2) supports PCIe Generation 3.0 x 4 speeds. The M.2 2242 Drive uses a adapter bracket p/n 02DL954 to accommodate for the larger M.2 2280 slot size.