Instead of buying a box spring and a frame for two beds that I ordered, I took a chance and ordered these. They are perfect! There is no need for a box spring with this foundation! The support is there that would be in a box spring, and the frames fit to each size bed exactly. Why spend the extra money when this is available? Plus it is higher off the floor than a regular frame, so anything you would like to store under your bed will fit perfectly! Wonderful product!