The Dream On Me Moonlight 130-Coil Crib and Toddler Mattress feature a heavy-duty innerspring with a firm infant side featuring CertiPUR-US certified layers for comfort. Flex Edge provides extra side edge support and safety when baby starts to pull up to a standing position or when the mattress is used with a toddler bed. The outer cover is made of an easy-to-clean material that helps you make sure your baby's sleeping environment stays sanitary. Meets Federal Standard Flammability Standard 16-CFR 1633. All Dream on Me mattresses are GREENGUARD Gold Certified for a healthy indoor environment for your baby