The Refresh Firm O Mattress is a great option for those who are looking for a comfortable and supportive sleep surface. The core of the mattress is made of one layer of 100% virgin rebonded foam. This type of foam is denser than regular polyurethane foam and provides superior support and durability. The mattress also features a quilted cover that helps to further enhance the comfort and support of the mattress. It also has a layer of breathable foam on top of the support core, which helps to keep the mattress cool and comfortable throughout the night. Overall, this mattress offers a great balance of comfort and support, making it an ideal choice for those who want a good night's sleep.