The Bedgear Germshield Mattress And Pillow Cover Set incorporates a lab-tested antimicrobial treatment to actively protect the fabric against 99% of certain germs, bacteria, microbes and odor to keep sleepers clean and healthy. It is also an allergen barrier to enhance long-term protection. The mattress cover is placed between the sheet and mattress protector, making it one bedding layer closer to the sleeper. The pillow cover is placed beneath the pillowcase to inhibit germs and allergens being exposed to the mouth and nose.