Nordic Pure 18x20x1M13+C-6 MERV 13 Plus Carbon AC Furnace Air Filters, Qty-6 Actual Size of Carbon Air Filter: 17 1/2 x 19 1/2 x 3/4 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