Polyester 100% Waterproof Protection: Polyurethane membrane provides protection from all other liquids to keep pillow safe from water, liquids, and stains. Zippered Closure: Fully seals the pillow so no leakage can occur. Easy To Clean: Soft polyester material is machine washable and wrinkle-free. Perfect For All Seasons: Breathable material helps keep head cool in the summer and warm in the winter. Two Year Unlimited Warranty: ForPro Professional Collection is one of the most trusted brands so you have 100% assurance that these pillow cases will last for years.