Safety 1st - Natural Tranquility Crib Mattress: * High-density, thermo-bonded core provides firm support * Fits all standard cribs and toddler beds * Meets federal flammability standards without the use of potentially harmful chemicals * Organic cotton sleeping surface is pure, soft and breathable * Removable cover is waterproof and washable * Dimensions: 52"L x 27.5"W x 5"H