9" Heavy Duty Premium Foundation - Standard Height, Available in Low-Profile and Bunkie Board OptionsThis 9 inch foundation delivers a stable, heavy duty base that prevents sagging and extends the life of your mattress. It fits standard mattress sizes, including Twin, Full, Queen, King, Cal King, and Twin XL, and works well with innerspring, hybrid, and memory foam mattresses. For King size beds, the foundation comes in two Twin XL boxes, making setup and handling easier while maintaining full support. The foundation also comes in alternative