The HP EliteBook 820 G2 Notebook Supports Single and Dual Drive Configurations. (One 2.5" Solid State Drive or Hard Drive and/or One M.2 NGFF (2242) or (2260) Solid State Drive) Note: The M.2 slot supports both M.2 (2242) and (2260) Drives by moving the metal mounting bracket to accommodate the form factor. If the 2.5" Drive was not Installed from HP, you will need the 2.5" Drive hardware kit p/n 730539-001 (Includes: 2.5" Drive bracket, connector adapter and screws) for installation.