This mattress has an extra firm steel innerspring made in the same construction as the innerspring used most often in adult sleep systems. The super thick steel border rod provides edge support for longer mattress life and the edge reinforcements around the perimeter help maintain the mattress’ shape. The padding is 100% cotton and free from the chemicals used in the manufacture of traditional foam padding. The infant side is covered with certified organic cotton that is grown without pesticides using eco-friendly farming methods that will not harm the environment. The toddler side is covered with a durable cotton twill. This mattress is PVC and Phthalate Free with no off-gassing and low VOC’s to help reduce the presence of chemicals in your child’s sleep environment. Lifetime manufacturer’s warranty.