This frame is designed for a mattress set measuring 78 inches by 80 inches. King size metal bed frame, EXTRA HEAVY DUTY with large 2.25 inch plastic wheels. This frame includes a cross support down the middle with two additional support legs. No tools needed for assembly. This frame comes with brackets at the head of the bed to use with a bolt-on headboard if you wish, it is not necessary. The bolts for the headboard are not included because different headboards take different size bolts. This frame will lift the box spring off the floor 7.5 inches.