AFB Bronze MERV 6 18x20x4 Pleated AC Furnace Air Filter. Pack of 2 Filters. 100% produced in the USA. 18x20x4 pleated air / furnace filter. Perfect for home or business use. Each purchase is for a pack of 2 filters that can replace any standand furnace or air conditioning filter. Manufactured by AFB in the USA, using 100% US components. MERV rating of 6. Basic pleat that filters pollen, mold, and dust. AFB is a leading manufacturer of air filters, made in a US factory and shipped direct to your door. AirFilterBuy: Breathe Better!