Zippered * Twin 39 X 75 X 9 * Excellent Retail Packaging! * Protects Mattress * Heavy 3 Gauge Plastic * Individually Sealed In A Poly-bag * Treated With Flame Retardant * Fits Both Mattresses And Boxsprings Up To 9 Thick * 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 *