The mini crib that we purchased came with a 1in mattress, but we really felt that since our guy would be spending the next 2 years in this crib that we should upgrade to a thicker, better quality mattress. We are very happy with this purchase and our Grayson seems to agree! He sleeps very soundly on this mattress. It offers just the right amount of firmness and support but still has a softness to the top layer. It's a very good mix and I would order it again.