EUC - Used for the first few months after that at Grandma's. Mini crib mattress 23.5" x 37.5" x 3" The included breathable cover has a waterproof backing.  Give your baby the best of all worlds – certified organic, waterproof AND breathable, all in a convenient, compact size. Provides a healthier and more practical approach to breathability while helping to protect Baby from harmful chemicals, flame retardants and hygienic challenges.