Features The Pillow covers will totally incase the pillow, giving it Maximum protection against dust-mite accumulation Stops the accumlation of dust-mites in the mattress 100% Waterproof design Easy to Maintain Unique design allows the body to breath Manufactured with a superior grade of cotton/polyester terrycloth with a thin but strong polyuerthane backing Pillow covers have zipper closure Reduces the occurrence of wheezing, congestion, sneezing, itchy watery eyes, headache,fatigue, rashes and weakened immune system,caused by dust-mites & their droppings li>The Rest-Guard covers are quiet. They will not make any annoying crinkling or scraping sounds with every movement Dimensions:21×25