From National Allergy® BedCare, this crib mattress cover features: woven cotton Dust Mite Proof: BedCare All-Cotton Mattress Covers eliminates exposure to dust mites and other allergens cotton barrier fabric is woven so tightly that only air can get through The mean pore size is just 2.6 microns Bed Bug Proof: As an added bonus, this bedding set is also bed bug proof Made with our patented BugShield system with an auto-lock zipper that will not backtrack when closed BugShield Bug Blocker is an added barrier that closes the last inch or so of the zipper from below to create a fabric shield under the zipper closure to doubly ensure that bed bugs will not be able to get in or out of the encasing crib mattress cover approx. 52" x 27" x 7" machine wash Made in the USA. National Allergy® BedCare All Cotton Allergy and Bed Bug Proof Crib Mattress Cover