23.5x23.5x1 (23.1 x 23.1) Filtrete Ultimate Allergen Reduction 1900 Filter by 3M (TM)

Filtrete 1900 Ultimate Allergen Reduction Filter by 3M (TM) 1900 Performance Rating. No competitor's 1"""" filter performs better. 26% more efficient then the Filtrete Advanced Allergen Filter. 93% effective at capturing large airborne allergens, such as pollen, mold spores and dust mite debris. Also captures small particles such as smoke, smog, household dust, pet dander, bacteria and particles that can carry viruses and tobacco smoke odors. Lasts up to 3 months.