The Lenovo V320-17ISK Laptop Supports Single and Dual Drive Configurations. (One 2.5" Solid State Drive or Hard Drive in Internal Primary Bay and One 2.5" Solid State Drive or Hard Drive in Optical Drive Bay) Note: 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 2nd HDD Board p/n 5C50N91537 for installation.