The mattress arrived when they said it would and it expanded to the 4 1/2 inch thickness as advertised. It is as comfortable as a 4 1/2 inch thick mattress, laying on a sofa bed frame, is going to be, so I would recommend this mattress. Very good quality for a good price. (However, if you want a very, very comfortable sofa bed, and you have space somewhere to store a second mattress, then put a lesser quality foam mattress under this one).