As we have a king size bed, we received TWO twin sized box springs. They came folded and already assembled, all we had to do was remove them from the box, flatten then, then finish zipping up the cover. They are super lightweight (our old foundation was solid wood and extremely heavy - we were actually concerned it may be too much weight over time for the bed frame). Both of us slept insanely well last night and there was less creaking from our bed. I'd definitely recommend!