The HP 15 Notebook 15-bs503na Comes in Different Drive Options from HP and Supports Single or Dual Drive Configuration. (One 2.5" Solid State Drive or Hard Drive and/or One M.2 NGFF (2280) Solid State Drive) or (One eMMC Solid State Flash Drive using a Adapter Board and/or One M.2 NGFF (2280) Solid State Drive) Note: When the eMMC Flash Drive is installed, the eMMC Flash Drive occupies the 2.5" Drive Bay using a Adapter Board. If replacing the eMMC Flash Drive for a 2.5" Drive, you will need the 2.5" Drive bracket p/n 924980-001 and connector board p/n 924995-001 and cable p/n 924927-001 for installation. (The M.2 slot supports SATA only Solid State Drives)