We have purchased 2 of these. First the queen for our 5th wheel bed. After sleeping on it for 2 days we ordered the king size for our bed at home. I always place a foam pad first and add the topper over the foam. These toppers are wonderfully soft and now I'm going to bed earlier just so I can snuggle up on it. No smell its looks like the old feather beds but not as heavy and does expand at least 3 inches.