My First Flip Mattress Crib and Toddler Mattress Combination, 27-1/4" x 51-5/8" x 5":

For babies, use the high-density foam side as it will provide your infant with the support they need
Perfect for infants from 0-12 months old
For toddlers, the mattress should be flipped over to reveal a layer of memory foam that contours to a child's body for an even weight distribution Perfect for toddlers from 1-5 years old
All My First products are constructed of CertiPUR-US certified flexible polyurethane foam technology
CertiPUR-US certified foams are:
Made without ozone deplenters
Made without PDEs, TDCPP or TCEP ("Tris") flame retardants
Made without mercury, lead and other heavy metals
Made without formaldehyde
Made without phthalates regulated by the Consumer Product Safety Commission