The distance between the holes to mount the headboard are around 3.5" and there are two possible hole positions to adjust the height as needed for different size mattresses and the headboard legs have adjustments slots to fit most insta-lock type bed frames. For mounting hardware, it requires 5/16" X 2 1/2" bolts, bolts not included. The overall dimensions are (WxDxH) 65" x 3.5" x 54".