Engineered to be compatible with Austin Air Jr HealthMate Air Purifier (HM200) Carbon pre-filter also captures larger particles before reaching filter, extending life of filter Recommended to replace once every five (5) years for maximum efficiency, or more often in harsh environments Contains one (1) Filter and two (2) pre-filters. Filter-Monster branded replacement filter for Austin Air Healthmate Junior Filter removes smoke, dust, pollen, pet dander, mold spores, and dust mites from the air. Includes Black Pre-filter to better conceal your filter in your unit. Compatible with Austin Air Jr, HealthMate Air Purifier.