Purchased this Slumber Solutions 12", full size, medium comfort, Gel Memory Foam mattress for our daughter's guest room where we sleep when visiting. Once opened, it was the 12" as stated. Christmas Eve we were there and how lucky were we. This one was firm yet it smoothly gives a little. At first, I thought I was not going to sleep. Holy cow, I slept through the night. In the morning, I stood up and could immediately walk away without the usual, omg, I hurt, I'm old, decrepit and miserable. This was like Rocky running up the flight of the stairs. My husband said this was much better than the one she had. It was good purchase.