Set of 5 MERV 13 Air Filters For a Box Fan Air Cleaner
Filter Kit contains 3 - 20X20X2 MERV 13 air filters and 2 16X20X2 MERV 13 air filters. This is enough to make a Corsi-Rosenthal Box Style Air Cleaner. Just add any 20" Box Fan and Tape! Shipping only available within the United States.