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. 100% recycled polyester padding for surface comfort. The cover is made from phthalate free vinyl that is reinforced with a layer of nylon filaments for extra tear resistance. It is also waterproof and can be wiped clean with a damp cloth. 25 year manufacturer’s warranty.