No Toil, Castle One-Year HVAC Furnace Filter, 20" x 25" x 1" MERV 8 - High Flow
No Toil, Castle One-Year HVAC Furnace Filter, 20" x 25" x 1". Compatible Devices: Furnace. While pleated filters need to be replaced about once a month, the Castle Air Filter lasts one year which is 4-12x longer than the others.