The GhostBed frame fit perfectly down inside the rails of our existing bed. It was easy to assemble with the help of my 6 year old Grandson. Our new mattress is the exact height of our old one, but the most important thing is how pleased we are with the comfort of our GhostBed. Great mattress, quick delivery, good price. As an added bonus our old bed on slats squeaked horrible my wife doesn’t even know when I come to bed now as I generally stay up longer. You’ll not be getting this one returned. Would also recommend the pillows.