Allergy Machine Replacement Filter Austin AirOnly use original Austin Air replacement filters to keep you Allergy Machine air cleaner working perfectly for many years to come. Each replacement filter comes with the main filter and one matching prefilter. White replacement filter fits the Sandstone, White, and Silver Allergy Machine air cleaners. The black replacement filter fits the Black and Midnight Blue Allergy Machine air cleaners. Easy to change. Takes about 10 minutes. Step 1 Open the box