Austin Air Standard Immunity Filter - White (FR444B)

The Austin Air Immunity Machine Replacement Filter FR444B is the 8-phase filter for the Immunity Machine, and it also fits the other standard-size Austin Air purifiers. It's made for people with weakened immune systems or autoimmune conditions, homes that are new or recently renovated, and busy shared spaces like classrooms, daycares, clinics, and offices.

Inside are eight types of filter media working together: two prefilters for larger particles, a four-part blend of carbon and mineral-based media for gases and odors, medical-grade HEPA for fine particles, and HEGA carbon cloth as the final stage. The filter works with the purifier's 360-degree air intake, so air gets pulled in and cleaned from every side. It has no electrical parts and runs off your existing unit.

Each filter is handcrafted in Buffalo, NY, and designed to last up to 5 years under normal residential use, one of the longest service lives on the market. Swapping it out is an easy do-it-yourself job, and the prefilter layers come already attached. In homes with heavy pollution or lots of pets, you may want to replace it sooner.

Product Features:

• 8-Phase Filtration: Eight types of filter media work in sequence to handle particles, gases, and odors in a single filter pack.
• Two Prefilters: Large and medium particle layers catch dust, pet dander, pollen, and mold spores before they reach the core filter.
• Four-Part Granular Blend: Carbon, treated carbon, and two mineral-based media absorb odors, VOCs, formaldehyde, ammonia, and nitrogen dioxide.
• Medical-Grade HEPA: Certified HEPA material captures 99% of airborne particles down to 0.1 microns, including viruses, bacteria, allergens, and microplastics.
• HEGA Carbon Cloth: Military-grade carbon cloth, originally developed for chemical, biological, and nuclear defense, adds a final layer against the smallest contaminants.
• Easy Upgrade: Drop it into a HealthMate, HealthMate Plus, Bedroom Machine, or Allergy Machine to get Immunity Machine filtration without buying a new purifier.
• Standard-Size Fit: Fits standard Austin Air units (model labels starting with HM4) but not Junior models or the Austin "it" personal purifier.
• Black Prefilter: The black outer prefilter matches darker Austin Air units like black, blue, and graphite.
• Long Filter Life: Designed to last up to 5 years under normal residential use, so you're not buying filters every few months.
• Everything Included: Comes with the main filter and integrated prefilter layers, so there's nothing extra to order.