Stretch Knit Polyester Dust Mite & Allergy Control Twin Duvet Cover 100% Polyester Made in US Stretch Knit Dust Mite & Allergy Control Twin Duvet Cover 100-Percent polyester laminated to a urethane membrane with a satin like feel An effective barrier to dust mites and allergens and is also waterproof Sewn with at least 12 stitches per inch and a heavy gauge rust proof nylon zipper Lifetime warranty, made in the USA