This topper is real memory foam, not the egg crate cheap material. Our last "memory foam" topper we purchased here was not memory foam at all, so we were very happy when this one arrived. It is supportive, since it is only 2 inches thick. You dont sink down to the mattress, which is a good thing. Has no smells. We also purchased a 2" feather topper that we placed on top of the foam and its heaven! That being said, this is not a real 4 pound density topper. density is the weight per sq ft. The shipping weight of the box was 28 lbs for a king size topper. A king bed is over 40 sq ft. A real 4 lb topper for our bed would weigh over 100 lbs. Considering those numbers, a real 4lb topper must be hard as a rock. Regardless, we are completely happy with this real memory foam topper and would recommend to others. Sweet Dreams!