Generic 3500 Replacement Filters Compatible with Air Doctor 3000 Series Air Purifier, fits Model 3000, 3500, and 3500i, 1 Premium Filter + 2 Activated Carbon Filter + 4 Pre-Filters

: 3500 replacement filters compatible with air doctor AD3000, AD3500, and AD3500i air purifier | :The original product has a registered design patent. We have adjusted our product appearance to avoid intellectual property infringement, while full compatibility and performance remain unaffected. Please purchase with confidence. | : Designed with more pleats for a greater expanded surface area, delivering superior performance and extended service life | : The 3500 filter works alongside the new fine sponge pre-filter and activated carbon filter | - : The package includes 1 premium filter, 2 carbon filters, and 4 sponge pre-filters. We recommend replacing the activated carbon every 6 months and the Main every 12 months for optimal performance (depending on your usage)