MERV 8 Pleated Filter 20″ x 20″ x 1″ Box 12
You should be changing your Ottawa Filters, ones every 3 months. For better operation performance changing your Ottawa filter ones, a Month is optimal.
Filtering media is supported by an expanded metal grid, allowing for a 95% open filtering surface area. Rigorously controlled pleat alignment and spacing assure uniform air travel across the entire surface of the filter.