A year ago I purchased a similar product to replace a 30 year old mattress. At 4 inches, it was comfortable if I did not turn over too quickly, but a bit thin and one had to be careful not to hit bottom, the plywood boards of the platform bed. My plan always was to create an 8 inch memory foam mattress of two of these, so when I could afford it a year later I bought the second one. I encased the two in a new mattress cover to keep them together. I have never slept so well in all of my lifetime, and Im going on 78, so it has been a lengthy test. The additional 4 pound test 4 inch memory foam pad was just the addition required to provide the most comfortable bed I have ever known. I am sleeping late for the first time in years. I am waking rested and without cricks in necks, backs, knees or shoulders.