The Dell Latitude 5550 Laptop Comes in 2 Different Drive Options from Dell and Supports Single Drive Configuration Only. (One 2.5" Solid State Drive or Hard Drive) or (One mSATA Solid State Drive) Note: The mSATA Drive and the 2.5" Drive are Installed in the same location using different drive caddys. If replacing the mSATA Drive for a 2.5" Drive, you will need the 2.5" Drive caddy p/n YH6GK for installation. If replacing the 2.5" Drive for a mSATA Drive, you will need the mSATA Drive adapter caddy p/n ND0X4F for installation. The mSATA Drive adapter caddy and the 2.5" Drive caddy use the same data cable p/n KGM7G to connect to the system board.