Engineered for optimal air flow for your baby's health and comfort, our Air-X® 2-Stage Performance® Crib Mattress is designed to provide a safe, comfortable, and clean sleep environment. A moisture wicking and refreshing cool touch cover conducts heat away from the body to maintain an ambient sleep temperature. Constructed with a 2-Stage Comfort Core, one side is specially designed with a safe, firm surface for babies 0-12 months. Flip the mattress over for a softer, adaptive side to support toddlers 12 months and up.