Philips PureProtect 3200 Series HEPA NanoProtect FilterCompatible with 3200 SeriesReplacement filters for Philips PureProtect 3200 Series air purifiers: AC3210, AC3220, AC3221. You can find your air purifier model on the bottom of the device. The package includes 2 filtersCompatible models require both filters to be used simultaneously for optimal filtration performance. Simply insert one at the bottom of your air purifier, and the other one at the top. Lasting filter up to 1 yearThe filters ensure