Austin Air Pre-filter for HM200/HM250
Austin Air no longer manufacturers the HM200 or HM250 but replacement filters for existing units are still available.
GSA Advantage Listing - ClearFlite Part Number 8016
A washable cotton pre-filter surrounds the main filter in the Austin Air HM400 or HM450. It gets the larger pieces of dust to prolong the life of the more expensive HEPA filter. It can be hand-washed but most users throw out the old one after a year and install a new one. To change filters, the unit is turned upside down, four screws removed, and the old filter pulled out. It is a fast and easy process.
This is the pre-filter for the HM200 and HM250 (also called the HM200 Plus) in both 110volt and 220volt models.
Austin Air Pre-filter for HM200/HM250 (note: the HM250 is also called the HM200 Plus)