This no-nonsense filter helps capture varying sizes of particles, from the large (lint, pollen, dust & pet dander) to the microscopic (smoke & smog). Opt for a Filtrete Allergen DefenseAir Filter to transform your central heating & 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 filters packaging, then choose 30, 60 or 90 days for your replacement countdown. When the lifespan is up, youll get a notification to change your filter Filter Type: Filtrete Filter Media & Activated Carbon; Filtration For: Dust; Fog; Lint; Pet Dander; Smoke; Width: 20"; Depth: 1".