The HP Envy 15 Notebook 15-k034tx Supports Either 1 or 2 Drives Depending on the System Board Installed. (Dual Drive Option on Select Models: One 2.5" Solid State Drive or Hard Drive and/or One M.2 NGFF (2280) Solid State Drive) or (Single Drive Option: One 2.5" Solid State Drive or Hard Drive) Note: Please verify there is a additional M.2 slot on the system board before ordering. If present, the M.2 slot supports SATA only Solid State Drives.