The Dell G15 5500 Gaming Laptop Comes in 2 Different Drive Options Depending on the Battery Installed and Supports Single and Dual Drive Configurations. (One 2.5" Solid State Drive or Hard Drive with the Smaller 3-cell 51Whr Battery Installed and/or One M.2 NGFF (2280) or (2230) Solid State Drive) or (Two M.2 NGFF (2280) or (2230) Solid State Drives with the Larger 4-cell 68Whr Battery Installed) Note: Models that have the larger 68Whr battery installed do not support 2.5" Drives due to the larger battery occupying the 2.5" Drive bay. When the M.2 (2280) or (2230) Drive is installed in the primary M.2 slot with the smaller 51Whr battery installed, the M.2 Drive occupies part of the 2.5" Drive bay. If installing a 2.5" Drive in models with the smaller 51Whr battery, you will need the 2.5" Drive caddy p/n WK14W and cable p/n 0YCJN for installation. If replacing the M.2 (2230) Drive to a M.2 (2280) Drive, you will need the M.2 (2280) thermal support bracket p/n YX03F for installation. M.2 slot 1 (SSD-1) supports M.2 (2280) and (2230) Drives by moving the drive mounting bracket to accommodate the form factor. M.2 slot 2 (SSD-2) supports M.2 (2280) Drives only.