The Dell Latitude 14 Rugged Extreme Laptop (7424) Supports 1, 2 or 3 Drive Configurations. (1 or 2 Drive Configuration: One M.2 (2280) Solid State Drive in the Primary M.2 Slot 1 and/or One M.2 (2280) Solid State Drive in the Secondary M.2 Slot 2) or (3 Drive Configuration: One M.2 (2280) Solid State Drive in the Primary M.2 Slot 1 and One M.2 (2280) Solid State Drive in the Secondary M.2 Slot 2 and One M.2 (2280) Solid State Drive in the Optical Drive Bay) Note: When a third M.2 Drive is installed, it replaces the optical drive. (The primary M.2 Slot 1 and the secondary M.2 slot 2 on the system board support SATA and PCIe NVMe Solid State Drives. The third M.2 slot 3 in the optical bay supports SATA only Drives)