Aller-Ease Waterproof, Dust Mite, Allergy Pillow Encasement, Set of 2, King 100% Polypropylene Imported Set of two King-sized pillowcase covers for blocking common household allergens Polypropylene non-woven fabric with polyethylene lamination Traps microscopic particles, dust mites and pollen; lets moisture vapor out Designed especially for allergy and asthma sufferers; recommended by allergists Machine or hand wash in cold; imported