I bought this to use as a trundlebed mattress for a toddler. I needed it to be less than 5 1/2 inches and it fits great. It is soft enough for him now but I am not sure in 5 years how it will work. I think it would be great to use on top of a mattress. It does has an odor but nothing too strong. Great price and works great for what I needed it for.