This is a 5" low profile heavy duty foundation. These are commonly used on platform beds where a lower mattress height is desired. Today's mattresses are generally thicker than older mattresses, so low profile foundations are also used on older beds to lower the mattress height so that the mattress doesn't "swallow" the headboard and/or footboard. Sometimes a bunkie board is preferred over a low profile foundation which is a solid thin base or "board" with an even lower height.

Please note that king size is comprised of 2 txl boxes (already included in the price).