Breathable and washable from cover to core, Newton's Essential crib mattress is a nighttime game-changer. The removable cover is made from a layer of soft, airy fabric, while the innovative Wovenaire® core is firm to encourage healthy development and ultra breathable for a sound night's sleep. The clincher? The entire mattress is washable, so you can keep it fresh for years.GREENGUARD Gold Certified, contributing to cleaner air in your home. Cover: viscose and polyester. Wovenaire® core: food-grade polymer. Single layer of soft, airy spacer fabric for breathability. Zippered cover for easy removal and quick nighttime changes. 4"-thick mattress is comfortable yet firm enough for baby's musculoskeletal development for a sound night's sleep. Cover: Machine wash cold, delicate cycle (zipped close); tumble dry low; do not bleach. Core: Hand wash in shower or with hose; air dry standing upright (avoid direct sunlight or heating elements). Made in USA of Domestic and Imported Materials.