Pack of 2 HEPA Replacement Filters for Alen air TF30 TF 30 for T100 and T300 Air Purifiers by LifeSupplyUSA Fits Alen Air T100 & T300 Air Purifiers compare to part # TF30 Washable Pre-Filter attached to the HEPA filter to capture large particles. Allow it to completely dry before replacing. Replace at least every 6 months with normal use Removes dust, pet dander, mold spores and pollen from the air