The Lenovo ThinkPad A275 Laptop Comes in 2 Different Drive Types and Supports Single Drive Configuration Only. (One 2.5" Solid State Drive or Hard Drive) or (One M.2 NGFF (2280) or (2242) Solid State Drive) Note: When the M.2 Drive is installed, the M.2 Drive occupies the 2.5" Drive bay using a 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 01HY565 and the PCIe SSD cable p/n 01HW969 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 bracket) and the HDD SATA cable p/n 01LV789 for installation. (The M.2 SSD is PCIe NVMe 3.0 x4 but runs at PCIe NVMe 3.0 x2 speeds due to the M.2 adapter limitations)