ULTRA PREMIUM MERV 11 LONG LIFE HOME FURNACE AC AIR FILTERS BEST ON AMAZON 6 PACK (16X25X1) 18 PLEATS PER FOOT, BETTER THAN OTHERS WITH 16 OR LESS! MORE FILTER MATERIAL = SUPER LONG LIFE BETWEEN CHANGES HIGH AIRFLOW / LOW RESTRICTION SINCE WE HAVE MORE PLEATS! LOWER RESTRICTION THAN MOST CHEAP MERV 8 RATED FILTERS! EASIER ON YOUR SYSTEM WHILE GIVING YOU CLEANER AIR!