the oreck dual max comes with twice the truman cell.the new and improved truman cell was designed to more efficiently capture pet dander, smoke pollen, dust and other allergens as the air passes through the filter. with ordinary air purifiers you could easily spend hundreds of dollars on expensive replacement filters. but the permanent oreck truman cell never needs replacing. and the dual max smart design includes an automatic indicator letting you know when it's time to clean the filter. and cleaning it is a snap. simply remove it soak it rinse it replace it and you're done. it's that easy. and now you can customize your experience. the oreck dual max is energy star qualified and our trademarked silence technology™. set on low for a peaceful night's sleep. set to medium for your everyday living, or kick it on high when you need a boost of extra cleaning power. the new oreck dual max has undergone thousands of hours of testing right here in our cookeville tennessee manufacturing and engineering facility resulting in our most powerful an