The Asus G751JL Laptop Supports Single and Dual Drive Configurations. (One or Two 2.5" Solid State Drives or Hard Drives) or (One 2.5" Solid State Drive or Hard Drive and/or One M.2 NGFF (2280) Solid State Drive using a M.2 bracket Installed in the second 2.5" Drive Bay) Note: There are two 2.5" Drive bays in this machine. The M.2 Drive uses a bracket p/n 13NB06F1M04011 and is installed in the second 2.5" Drive bay. If adding the second 2.5" Drive, you will need the 2.5" Drive caddy p/n 13NB06G1AM0301 for installation. (The M.2 slot supports PCIe AHCI only Solid State Drives)