msi slotMSI’s exclusive EZ M.2 Shield Frozr II and EZ M.2 CLIP II make M.2 installation seamless. Insert the SSD card into the slot and press it down to lock it in place with the clip. As fasten the SSD,B key slot for ‘B’Key card (also known as Socket 2) (SATA) M key slot in ‘M’Key card (also known as Socket 3) (PCIe x 4) B+M Key cassettes are available for both cassette slots. Check HDD and SSD support specifications.