100% Waterproof Feather Proof Zippered Protection - Microscopic pores in the 100% Waterproof Polyurethane membrane provide protection from all other liquids to keep your pillow safe from saliva, perspiration, liquids, stains, sweats, and anything wet. Zipper closure fully seals the pillow. Carefully stitched with an auto-locking slider does not allow accidental opening of the zipper, making it the perfect pillow encasement that guards against anything that can spoil your night. Makes Old Pillows New, Prolongs Pillow Life: 4-Pack Standard 20x26, Queen 20x30, and King 20x36 Inches pillowcase cover encasements are breathable smooth polyester which is easy to clean. The pillow protectors are perfectly machine washable. Luxury pillow protectors with a zipper have premium features of cotton pillow protectors. Breathable with Smooth Fabric - Our Standard Luxury pillow covers encasements are made in all sizes: Standard 20" x 26", Jumbo / Queen 20" x 30", King 20" x 36", with a smooth fabric top. Miracle membrane backing keeps the body cool in summer and warm in winter. They come in packs of 2 and packs of 4 styles. Waterproof Pillow Covers are backed against manufacturing defects. Washable Easy Care: We manufactured our product with extreme care and welcome any suggestions, but if you do not like the product, you can do a hassle-free return procedure. Long Life: Our 4-Pack of 4 Standard Queen King-size pillowcase covers are encasement-style pillowcases made from strong fabric that can be used for many years.