01 Ago Nordic Pure 20x25x4 (19_1/2 x 24_1/2 x 3_5/8) Pleated 19.5″ x 24.5″ x 3.6″
With the 4" and 5" air filters there is a wider variance between the nominal and actual size depending on the manufacturer. A human hair is about 70 microns wide. This high performance air filter will outperform non-electrostatic fiber-glass filters, washable filters, and poly disposable...