Austin Air Pre-filter for HM400/HM450
GSA Advantage Listing for government buyers price
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.
The Pre-filter for the HM400/HM450 is ClearFlite Part No. 8009. Austin Air Model F400B
It works in both 110volt and 220volt models.