This Sealy Premier Posture Dual Sided Crib Mattress fits both standard size cribs and toddler beds so you can use it for years. A soft, PVC-free cotton cover provides premium comfort and luxury; lock-stitched waterproof binding helps keep any leaks from seeping inside. The infant side features firm layers, while the toddler side offers soft cushioning. With 204 ultra-firm support coils, this crib mattress is one of the firmest you can find.