SafeRest Twin Size Classic Waterproof Lab Certified Bed Bug Proof Zippered Mattress Encasement (Fits 6-9 in. H) - Designed For Bed Bug, Dust Mite and Fluid Protection Polyester Independently lab tested and certified bed bug entry, escape and bite proof Encases the mattress on all 6 sides against bed bugs while protecting the surface against dust mites, bacteria, fluids, perspiration and urine Exclusive Micro-Zipper technology prevents all stages of bed bugs from passing through the zippers teeth 360 Secure zipper closing feature prevents accidental openings by sealing the end zipper traveler with a Velcro flap 3-year full replacement warranty and machine washable (registered with the FDA as a class 1 medical device)