***absolutely useless without a box spring. The mattress literally slips through the bars in the middle of the bed. After an hour and a half of building, I was so excited to lay down on my new bed on the new frame, only to have the mattress fold in half from lack of support. The frame has four bars that go across the bottom, and if you don’t have a box spring, the mattress will fold and concave directly into those holes. My last frame worked perfectly without the box spring, so now I’m stuck in this ridiculous position where I have to distribute my weight perfectly every time or risk falling through. The bed looks nice, it was very easy to put together, and although I’m bitter about having to spend an extra $150 for a box spring, I enjoy the frame as a whole.