20x25x4 MERV 13 ( MPR 2200 ) AC Furnace 4" Inch Air Filters by Glasfloss Industries. 6 Pack. Actual Size: 19-1/2" x 24-1/2" x 3-3/4"

Exact Size: 19-1/2 x 24-1/2 x 3-3/4, Nominal Size: 20x25x4 Filtration Rating: MERV 13. rating 1900 to 2200, or FPR 10 rating. Effectively captures and blocks small-particles such as virus carriers, bacteria, allergens, smog, smoke, lint, dust, pet dander and pollen.