Welcome to a fresher, healthier indoor environment! Get the most out of your GT3000 and pureAir 3000 Whole-Home Air Purifiers.If your environment has any severe air quality issues (i.e. smoke, pets, airborne grease, dust, or paint) you should use a Harsh Environment Pre-Filter to protect your unit and keep it running at peak performance for many years to come. Simply remove the back grill and place the pre-filter on the existing filtration assembly. — 12 Harsh Environment Pre-Filters Per Pack (1 Year Supply)

Areas That Need Harsh Environment Filters:

• • Indoor smoking areas

• • Habitat with multiple pets

• • Commercial kitchens

• • Spaces with dust, paint, or grease

• • Heavily polluted areas