Nordic Pure 24x24x4M11+C-1 MERV 11 Plus Carbon AC Furnace Air Filters, Qty 1 Actual size of carbon air filter: 23 3/8 by 23 3/8 by 3 5/8 One convenient air filter - MERV 11 pleated plus activated carbon Odor absorbing activated carbon A simple solution for controlling both odors and dust particles Nordic Pure Manufacturer Direct since 1960 - Made in the USA