*Not sure of size* Open box Support your mattress with a heavy duty steel bed frame designed to support mattresses of varying sizes. It is the only frame you’ll need as you transition from Twin to Full to Queen. If your kids are growing up and need a bigger mattress, there’s no need to buy another frame thanks to the STRUCTURES Heavy Duty Adjustable Metal Bed Frame. The outside rails create a sturdy structure and the center bar adds extra support for your mattress and box spring. Four rollers and the center support glide help you easily move your bed frame without tugging on carpet or leaving large indents on your rug