16 Inch HEPA Cartridge, Molded, for Large Amaircare Units Made Prior to 2016 16 Inch HEPA Filter Cartridge 90-A-16NA-MO, molded cartridge,for Amaircare 3000, 3050, 4000, 4050 and 4000V, 5000V HEPA Air Purifiers. No Air Purifier is Included: 16 Inch HEPA cartridge. Note: Use in Units Made Prior to 2016. 100 square feet of HEPA filtration material captures the smallest particulates. In about 2-5 years, particulates clog this HEPA filter. Significant airflow reductions occur. Replace HEPA cartridge sooner if air cleaner is located in a dusty environment. Always replace a HEPA air filter if an air purifier is turned off for more than 3 to 5 days. HEPA is a medium in which bacteria, viruses, etc. can grow if moisture collects in the filter media. Constant air flow keeps the HEPA filter media dry and free of such contaminants. Note: Filters are not returnable unless deemed defective after inspection by the manufacturer. Please be careful to order the correct size filter for your air purifier.