Foundation - Standard 9 Split King 2 RequiredIts a lot about the base. The 1 2 combination of a supportive mattress and well built foundation is just what you need for restful sleep. We designed this king foundation to last with solid wood engineering and a diagonal bar for strength and durability. Smooth nonskid surface holds every style of mattress in place including hybrid memory foam and innerspring mattresses. Please note a king mattress requires two twin foundations sold separately.