This mattress cover protects your mattress from spills, stains, and perspiration. The tightly knit polyester fabric blocks out dust mites, pollen, pet dander and other household allergens that can trigger asthma and allergies from settling in your mattress. The mattress cover fully encases your mattress with a zippered closure on the front half that provides a layer of protection between you and the allergens that collect in your bedding while preventing new allergens from entering. Plus, this cover is machine washable, so you can easily keep it fresh.