To keep your 3M Filtrete air purifier working at optimum levels, the Ultra Clean Replacement Standard Filter is designed for use with the FAP-03 Filtrete Room Air Purifier. Absorbing dust, mould spores, pollen and cigarette smoke, it is easy to switch in and out of your purifier for a consistently high standard of operation. 3M recommends a filter change for every 3 months of continuous use.