I bought this for my guest bedroom to refresh an old mattress. It came twisted in a little ball and I could barely unfold it, but after leaving it unraveled laying on the bed within 48 hours it was flat and had expanded to its full size. It was not fully unraveled in 24 hours as the packaging said, but still it unraveled very nicely. It is very comfortable and I recommend it. It is slightly smaller than the queen mattress size, but once the mattress pad is on it, it doesn't matter. They say that it is made to be slightly smaller. No smell after the 48 hours.