Trion Air Bear T08-20251-6P - 20" x 25" x 1" Pleated Air Filter (6-Pack), MERV 8

Standard size 1" filters. Actual size is 1/2" smaller on the length and width, and the thickness is .75" MERV 8 efficiency rating This listing is for 6 individual filters Manufacturer recommended replacement every 1-3 months