6 Pack of 20x20x4 MERV 13 Pleated 4" Inch Air Filters by Glasfloss. Actual Size: 19-1/2 x 19-1/2 x 3-3/4 Filtration Rating: MERV 13. Comparable to 3M/Filtrete MPR rating 1900 to 2200, or FPR rating 10. Protects from pollen, dirt, dust, pet dander and virus carriers, smoke, smog, lead dust, oil smoke and micro allergens. Note: Does not replace 5" inch or 4-3/8" Depth filters. Please check actual filter size needed.
