Fette Filter True HEPA Filter Compatible GermGuardian FLT4825 Models AC4300/AC4800/4900 Series Air Purifiers - Filter B. (HEPA & Pre-Filter) Multiple levels of cleaning include HEPA, Pre-Filter/Activated carbon layer to help improve indoor air quality Compatible with original GermGuardian FLT4825 Filter; Easy to install Activated carbon filter reduces common odors from pets, smoking and cooking Compatible with AC4300/AC4800/4900 Series Air Purifiers One high-quality filter set manufacturered by Fette Filter