Austin Air Standard Pre-Filter - White (F400B)

Replacement large particle pre-filter for standard size Austin Air purifiers, in white. This is the outer layer that takes the first pass at the air, catching dust, hair, pet dander and anything else over about 10 microns before it reaches the media underneath.

Swapping it is the cheapest thing you can do for your unit. The main filter is built to run five years, and it gets there by not clogging with the big stuff. A loaded pre-filter restricts airflow and puts that work on the HEPA layer instead, so Austin Air recommends replacing the large particle pre-filter once a year while the main filter stays in place. Homes with pets, heavy dust or high pollen may want to change it more often.

It fits every standard size Austin Air purifier, including the HealthMate®, HealthMate Plus®, Allergy Machine®, Bedroom Machine® and Pet Machine®. Installation takes a minute with no tools. White is the usual match for white, sandstone, silver, pink and baby blue units.

Product Features:

• First Stage Filtration: Captures particles over 10 microns, including dust, hair and pet dander.
• Protects Your Main Filter: Keeps large debris off the HEPA media so the filter underneath reaches its full service life.
• Annual Replacement: Low cost consumable, changed about once a year in a typical home.
• Fits All Standard Size Units: Works across the standard size Austin Air lineup.
• Tool Free Install: Wraps on in under a minute.

Not sure of your size? Look for the label on the underside of your unit. Standard size models are labeled HM4, like HM400.