The HP ProBook 440 G3 Notebook Comes in Different Storage Configurations and Supports Either 1 or 2 Drives Depending on the System Board Installed. (Single and Dual Drive Options with a 6th Gen Intel Core i3/i5/i7 Processor: One 2.5" Drive and/or One M.2 NGFF (2280) Solid State Drive) or (Single Drive Options with a Intel Pentium 4405U or Celeron 3855U Processor: One 2.5" Drive or One M.2 NGFF (2280) SATA Solid State Drive using a M.2 Drive Bracket) Note: When the M.2 (2280) Drive is installed in models with a Intel Pentium or Celeron Processor, the M.2 Drive occupies the 2.5" Drive bay by using a M.2 Drive bracket. If replacing the M.2 Drive for a 2.5" Drive in models with a Intel Pentium or Celeron Processor, or adding a 2.5" Drive to models with a 6th Gen Intel Core i3/i5/i7 Processor, you will need the 2.5" Drive cover p/n 826382-001 for installation. (The HP ProBook 440 G3 support M.2 SATA only Solid State Drives)