Keep your air purifier operating at peak performance. Filter captures up to 99.97% of airborne particles and microscopic allergens. Replacement media must be used with pre-filer: HRF-AP1. For best performance, replace once each year. Air Purifier Filter Type: HEPA; Filtration For: Allergens; Dust; Mold Spores; Pet Dander; Pollen; Smoke; Air Cleaner Compatibility: Honeywell® HPA100, HPA200, HPA300; Width: 6.75".