First off my mattress doesn’t fit, I’m assuming because the box spring is too thick. However, I don’t think it specifies the distance between the worsen slats and the headboard to determine if both the mattress and box spring will fit. Also all of the pieces fit together perfectly, but why is it that the slabs have to be screwed into the support beams on the side rails when there are no holes in the support slats. So basically you’re screwing a non existent hole into the support slats all the while they are cracking. Regret getting this.