The Lenovo ThinkBook 14 G3 ACL Laptop Comes in 2 Different Drive Options Depending on the Battery Installed and Supports Single and Dual Drive Configurations. (Models with the Smaller 3-cell 45Whr Battery Installed: One 2.5" Solid State Drive or Hard Drive and/or One M.2 NGFF (2280) or (2242) Solid State Drive) or (Models with the Larger 4-cell 60Whr Battery Installed: Two M.2 NGFF (2280) or (2242) Solid State Drives) Note: Models that have the larger 60Whr battery installed do not support 2.5" Drives due to the larger battery occupying the 2.5" Drive bay. The M.2 (2242) Drive uses a adapter bracket p/n 5B40S22074 to accommodate for the larger M.2 (2280) slots. If the 2.5" Drive was not installed in models with the smaller 45Whr battery, you will need the 2.5" Drive bracket p/n 5B40S22035 and cable p/n 5C10S30169 for installation.