The Lenovo V320-17IKB Laptop Supports up to 2 or 3 Drives. (One 2.5" Solid State Drive or Hard Drive in the Internal Primary Bay and One 2.5" Solid State Drive or Hard Drive in the Optical Drive Bay and (Optional) One M.2 NGFF (2242) Solid State Drive) Note: The M.2 (2242) slot is only on select models, please verify your model has the M.2 slot before ordering. The second 2.5" Drive replaces the optical drive when installed. If installing the second 2.5" Drive in replace of the optical drive, you will need the 2nd HDD bay p/n 5M20N82345 and the 2nd HDD board p/n 5C50N91537 for installation. If the 2.5" Drive was not installed from Lenovo, you will need the 2.5" Drive caddy p/n 5B40N82219 for installation.