The Dell Vostro 13-5391 Laptop Supports Single and Dual Drive Configurations. (One M.2 NGFF (2280) or (2230) Solid State Drive in the Primary M.2 Slot and/or One M.2 NGFF (2230) Solid State Drive in the WWAN M.2 Slot) Note: The second M.2 (2230) is supported in Black PC models with WLAN configurations only. The second M.2 (2230) Drive utilizes the WWAN slot when installed. When the M.2 (2230) Drive is installed in the primary M.2 slot, it uses a adapter bracket p/n 07HMH to accommodate for the larger M.2 (2280) slot. The primary M.2 slot supports M.2 (2280) and (2230) PCIe NVMe 3.0 x4 Solid State Drives. The secondary WWAN M.2 slot supports M.2 (2230) PCIe NVMe 3.0 x2 Solid State Drives only.