40% Certified Organic Cotton/ 60% Polyester SECURE FITTED DESIGN: Soft micro-weave fibers are comfortable for baby and stretch securely to fit both foam and innerspring full-size crib and toddler mattresses CRIB MATTRESS ENCASEMENT: Easy-to-use zipper technology; designed to use underneath crib pads and fitted sheets WATERPROOF PROTECTION: 100% waterproof layer protects baby's mattress from leaky accidents, moisture and spills for a fresher, cleaner sleeping surface EASY-TO-CLEAN: Machine washable and dryer friendly for easy cleaning SAFETY & QUALITY: Lab tested for safety, quality and durability to ensure long-lasting use