They provide you with the wooden cross pieces to lay the box frame on. On each on of those cross pieces, you have to install one vertical member underneath to brace from the floor to the cross piece. The vertical member has a piece of plastic on sit that rests on your floor. I have hardwood floors and the piece slides when I'm in the bed and causes the middle of my bed to dip because it looses it brace when the vertical member slips. Going to cut up some 2" x 4" to make my own braces that won't slip.