Soft, breathable, lightweight cotton muslin fitted sheet will encourage sweet zzZs. Fully elasticized, designed to securely fit standard US crib mattresses of 28 x 52 x 6 inches. Your baby will enjoy the comfort of 100% premium cotton muslin, so you both rest easy. SwaddleDesigns cotton muslin is pre-washed to increase softness and we use premium cotton yarns to increase durability and minimize pilling. Coordinates with a variety of our quality baby essentials. Machine wash gentle.