Dream On Me, Butterfly 3” Two-Sided Fiber Portable/ Mini Crib Mattress inner core is constructed with extra firm Eco-fiber for infant side, comfort layer for an inviting, comfortable, environment for your sleeping toddler. This mattress is proudly constructed of quality materials and workmanship in the USA. Lead and phthalate tested this mattress passes the Federal Standard Flammability Standard 16 CFR 1633. Designed to fit a standard 24” x 38” Portable/Mini Crib. As parents are looking for more space-saving furniture mini and portable cribs are ideal for apartment/ smaller homes and Dream On Me Butterfly mattress fits most mini cribs (not designed for standard cribs or pack 'n plays).