The Dell Latitude-5520 Laptop Supports Single and Dual Drive Configurations. (Two M.2 NGFF (2280) or (2230) Solid State Drives) Note: Both of the M.2 slots support M.2 (2280) and (2230) Drives by moving the SSD holder screw to accommodate the form factor. (M.2 slot 1 supports Generation 3.0 x4 NVMe Drives and M.2 slot 2 supports Generation 4.0 x4 and 3.0 x4 NVMe Drives)