Premium Tight Weave: Usa Lab Certified NSS Pillow Protectors are made from Premium 100% breathable and best to be used with Down ,Feather Pillows . Premium Cotton Sateen Fabrics which have extreme tight weave and a pore size of 3-4 Micron .Which is a perfect breathable encasement cover does not allow anything to go through. Our Bed Pillow Covers are easy way to control itching,sneezing, itchy throat, stuffy nose and it help ease asthma so you can get a good night??s sleep.Hotel Grade Anti Shrinkage Cotton Fabrics: Our Pillow Covers are made with hotel grade ultra plush fabrics that will not shrink after washing. Cotton white pillow cases has been treated for anti shrinkage ,exta softness and designed to bear dozens ,hundreds of washes without changing the texture of the fabrics.Oeko Tex Certified Cotton Zippered Pillow Case Protectors: Our 4 Pack King White Pillow cases are make with goods quality zipper with auto locking slider that does not move on its own. Keeping the pillows fully secured as well as encased from all sides.They are made according to ethical manufacturing standards and Oeko tex certified.Breathable with 100% Premium Fabric ?CPillow cases are made with breathable cotton fabrics, that allows air to pass through keeping cool in summer and warm in winter.Our Cotton white pillow cases are made in all sizes Standard,Queen,King with cotton fabrics that are soft.They come in 2 pack and 4 pack style. Our pillow protectors are non pvc ,vinyl and free from coatings or membranes.Life Time Replacement:We are confident about our pillow protectors as we use superior raw materials to make them and they are backed by life time replacement, feel free to contact us if you face any problems. We manufactured our product with extreme care and welcome any suggestions.