20x20x1 Dust & Pollen Pleated Filter MERV 8 (12 Pack) 100% Synthetic Media. Exact Size: 19-1/2 x 19-1/2 x 7/8 Designed to meet the performance and the maximum filter life. Glasfloss Air Filters have met MERV 10 regulations instead of MERV 8. 90-day filter life.