Rest assured knowing your baby is sleeping on the best crib mattress for breathability, safety and comfort. 2-stage lightweight, convertible mattress. One side is firm and supportive for infants. The other side is soft and adaptive for toddlers. The waterproof barrier protects the core for a clean and healthy sleep environment. Removable, washable inner layer is engineered with patented Air-X technology to enhance airflow and provide a comfortable sleep surface.