This California King mattress coverprotects your expensive mattress and your health, too. The mattress coveris fitted, like a bottom sheet. Its hospital-quality, waterproof, allergen barriers protect your health from mold, dust mites and other allergens that come to live in even the best mattresses. Comfortable, durable Restguard mattress covers by Taperly Products are manufactured with a superior grade of cotton/polyester terrycloth thermo bonded to breath-cool polyurethane backing. The polyurethane laminate cover material is warranted for 10 years against defects in workmanship and materials. The Rest-Guard products are also hot water washable, machine washable and dryer safe.