Our Allergy Relief Bedding Is Designed Specifically To Prevent Dust Allergens From Becoming Airborne * The Membrane-free Tight-weave Construction Prevents Dust Allergens And Pet Dander From Becoming Airborne * No Membrane Means The Most Comfortable And Cool Night?s Sleep And Allergy Relief * All Of Our Covers Are Laboratory Tested And Efficient Against Dust Allergens And Pet Dander * Zippered Mattress Cover * Twin 39 X75 X9 * Six Gauge Vinyl * Heavy Duty And Durable * One Cover Per Package * 100% Waterproof * Fire Retardent * Notice To California Consumers: Warning: This Product Contains Chemicals Known To The State Of California To Cause Cancer And Birth Defects Or Other Reproductive Harm *