Purolator HE-40 24x24x1 Merv 8 Pleated AC Filters and Furnace Filters High Dust Holding Capacity Actual Size: 23-3/8 x 23-3/8 x 3/4 $6.75 Each - 1 Case of 12 Total $81.00 The Purolator HE-40 Provides 90-93% Average Arrestance and Maximizes Dust Retention Capabilities