Nordic Pure 20x20x4/20x20x5 (4-3/8 Actual Depth) Honeywell FC100A1011 Replacement MERV 13 Pleated AC Furnace Air Filter Plus Carbon, Box of 1 Actual Size of Carbon Air Filter: 19 5/8x 19 7/8 x 4 3/8 Activated charcoal flat panel added to increase odor control Removes tobacco and fireplace smoke, along with all contaminants removed by a MERV 12 filter Ideal for customers looking for superior filtration but needing an odor control element Made in the USA