bought original mattress and found it very uncomfortable as in the middle of the bed a hump was forming and making our sleep very uncomfortable. I called sears and they took back the mattress saying that the reason for the hump in the middle was because the guys that set it up did not put support in middle of box spring. ok, I bought that excuse or reason and they sent me another mattress and this time set all up properly, but after a short time of maybe 2mths the hump also started to form of this one, now sears in Canada is gone out of business and I can't find the original bill and the return as well, so I guess I am out of luck! Now besides the issue with the middle of the mattress the edges are hard as rocks. The mattress is also hard as rocks, be very aware of what your buying because in my opinion this is a disaster.