Distinct Dual Density provides maximum dust loading and dust retention. The coarse, open structure of the white, air entering layer is designed for depth loading. The orange, dense downstream layer prevents finer dirt from passing through the media.

Unique  Adhesive uniformly coats one-half of the total fibers (downstream layer) during the actual formation of the media

Absolutely the most advanced and effective portable air purifier available. Better than HEPA!