Keep your Amaircare 2500 or 2550 air purifier ( Made Prior to 2016 ) that uses a molded HEPA filter working at maximum filtration capacity. Change pre-filters every 3-4 months and the VOC canister at least once per year. Filter replacements coordinate with 8 inch molded HEPA filter units. Plus Annual Filter Kit includes 3 carbon prefilters and 1 VOC canister. Replacement filter kit is for the Amaircare 2550 air purifier (not included) and the Amaircare 2500 HEPA air purifier (not included).