More babies sleep on a Sealy than any other crib mattress brand. Sealy Baby crib mattresses are known for superior quality, safety and support. The Sealy Butterfly crib mattress collection has a variety of waterproof covers to choose from. Made with durable, lightweight high-density foam. Locally made, non-imported foams are CertiPUR-US Certified for durability and quality. A reinforced tear-resistant laminate cover zips over the foam core. 100% waterproof surface and a sleek, seamless design. The entire crib mattress is GREENGUARD GOLD Air Quality Certified for a healthier environment. Square corners create a snug fit in cribs and toddler beds. Popular crib mattress-in-a-box safely expands and rolls out flat to fit all standard size cribs and toddler beds. Crib mattress measures 52x28 inches. Passes ASTM crib mattress standards for firmness, fit and lasting durability. Warranty on workmanship and materials.