We are using this on the bottom of my boys trundles and I have to say, they are really nice for this purpose. My 16 yr old daughter is sleeping on one as we redo her room, and she wants them for her bed as well. We have the same brand in the 11 inch on the top for both boys, and I just purchased the 14" queen for my husband and I. Just a note though, firm is more like medium firm, but I am expecting that after sleeping quite nicely on my son's firm lol