HP302 Neverchange Replacement Filter Compatible with Shark HP302/HP301/HP201/HP202/UA205/AP1000/HC501/HC502 Air Purifier MAX, 4-in-1 H13 Grade True HEPA Filter, Part # HE2FKBAS, HE2FKBASMB,HE3FKPET

Very reasonably priced. The "Never-change" purifier does need to have the filter changed every 5 years or sooner, if you have two large harry dogs as I do. My last filter lasted almost 3 years even with the amount of hair my dogs produce. We vacuum several times a week, but we know the dogs carry in dirt and allergens with them when they come in from outside. This purifier helps to keep our air clean and the low maintenance of buying a filter every 3 to 5 years is very impressive. I have asthma and have found this to be very helpful for my breathing.