The HP Envy 15 Notebook 15-1007tx Comes in 2 Different Drive Options from HP and Supports Single Drive Configuration Only. (One 2.5" Solid State Drive or Hard Drive) or (One 1.8" Solid State Drive or Hard Drive in a Adapter Caddy) Note: When a 1.8" Drive is installed, the 1.8" Drive occupies the 2.5" Drive bay using a adapter caddy. If replacing the 1.8" Drive for a 2.5" Drive, you will need the 2.5" Drive caddy p/n 576827-001 and cable p/n 576828-001 for installation. If replacing the 2.5" Drive for a 1.8" Drive, you will need the 1.8" adapter caddy p/n 576829-001 and cable p/n 576830-001 for installation.