This is the second memory foam mattress that I have owned. The first one was a Serta. I purchased it here on "O" and it lasted 10 yrs before I felt it was time to get a new one. This memory foam appealed me because it had the same quoted thickness and density rating as my Serta,with the addition of a cover, however it is extremely hot and you sink to the bottom as soon as you lie on would have gone back it I could get it back into the box. The topper has a very luxurious cover on it but both the cover and the topper expand shortly after placing on the bed to "hang over both sides of my king sized bed".