I bought this for my granddaughter's bed. She has an old mattress that belonged to my kids and was a little saggy. This mattress topper was perfect. It is so comfortable and she loves sleeping on it. It was compressed when it arrived. I opened the package and let it air out like the instructions stated. It initially had a chemical smell. I opened the window and turned the ceiling fan on while it was puffing up. The smell went away within hours.