PRE-FILTER 6-Pack for Germ Guardian AC4800 Series(AC4825, AC4825e) Filter B FLT4825 True HEPA Replacement to IMPROVE Indoor Air Quality & Helps REMOVE Odor by Complete Filtration (CFS) Premium Carbon Activated PRE-FILTER 6-Pack for Germ Guardian AC4800 Series(AC4825, AC4825e) Filter B FLT4825 True HEPA Replacement to IMPROVE Indoor Air Quality & Helps REMOVE Odor by Complete Filtration (CFS) Carbon Activated Pre-Filter 6-pack Made in the USA From CFS These Filters Are For Use With The GermGuardian FLT4825 HEPA Filter Each filter is 4.8"x15.75"