20x20x4 merv 11 ( mpr 1000 ) ac furnace 4" inch air filters. qty 6. actual size:19-1/2" x 19-1/2" x 3-3/4" actual size: 19-1/2 x 19-1/2 x 3-3/4 | nominal size: 20x20x4 filtration rating: merv 11. comparable to mpr rating 1000 to 1200, or fpr 7 rating. effectively captures and blocks small-particles such as allergens, smog, smoke, lint, mold, bacteria, dust, pet dander and pollen. utilized for healthier living environments.
