Aller-Free 6-Sided Complete Mattress Encasement/Protector, Twin, White 100% Polyester Imported Aller-Free Mattress Encasement is a central part of your bed bug control strategy; Provides a clean and hygienic sleeping environment for all ages The ultra-dense low-micron polyester barrier protects you and your family from dust, dust mites, allergens and bed bugs Fully encases your entire mattress and/or box spring for total 360-degree protection; fits up to 18-inch mattresses A fine tooth zipper spans the total width and length on two sides for easy installation and removal; Binding over the zipper additional protection Elasticized corners create a custom fit; Twin size measures 38-by-75 Inch; Machine washable in cold water; Tumble dry on low heat