17.5x21x1

Glasfloss ZL 17.5x21x1 MERV 10 (FPR 5-6) AC Furnace Air Filters. (Box of 6). Actual Size: 17-1/2 x 21 x 7/8

Actual Size: 17-1/2 x 21 x 7/8 | Nominal Size: 17.5 x 21 x 1 ? Filtration Rating: MERV 10. Comparable to MPR rating 600 to 800, or FPR 5-6 rating. Improved MERV 10 Filtration with similar air flow and resistance as a MERV 8 filter. Durable & Long...