The Lenovo ThinkPad P52s Laptop Comes in 2 Different Drive Options from Lenovo and Supports Single and Dual Drive Configurations. (One M.2 NGFF (2280) Solid State Drive in a Adapter Bracket and/or One M.2 NGFF (2242) Solid State Drive in the WWAN Slot) or (One 2.5" Solid State Drive or Hard Drive and/or One M.2 NGFF (2242) Solid State Drive in the WWAN Slot) Note: When the M.2 (2280) Drive is installed, the M.2 Drive occupies the 2.5" Drive bay using the M.2 adapter bracket that is installed in the 2.5" Drive caddy. If replacing the 2.5" Drive for a M.2 Drive, you will need the M.2 adapter bracket caddy p/n 01AY476 and the PCIe SSD cable p/n 01YR466 for installation. If replacing the M.2 Drive for a 2.5" Drive, you will need the 2.5" Drive caddy (remove from M.2 SSD adapter bracket) and the HDD SATA cable p/n 01ER034 for installation. The M.2 (2280) Drive is PCIe NVMe 3.0 x4 but runs at PCIe NVMe 3.0 x2 speeds due to the M.2 adapter bracket limitations.