This no-nonsense filter helps capture varying sizes of particles, from the large (lint, pollen, dust and pet dander) to the microscopic (smoke and smog). Opt for a Filtrete™ Allergen Defense Air Filter to transform your central heating and cooling system into a whole-home air filtration operation. Designed with exclusive Filtrete™ Brand 3-in-1 technology from 3M to trap unwanted air particles while letting cleaner air flow through. Create a change countdown in the Filtrete™ Smart app. Simply use the app to scan the barcode on your filter's packaging, then choose 30, 60 or 90 days for your replacement countdown. When the lifespan is up, you'll get a notification to change your filter. Air Purifier Filter Type: Filtrete® Filter Media and Activated Carbon; Filtration For: Dust; Fog; Lint; Pet Dander; Smoke; Width: 20"; Depth: 1".