20x20x1 MERV 8, MERV 10, MERV 11 & MERV 13 air filters for your furnace, air conditioner, heat pump, or HVAC system. The 20 x 20 x 1 high-quality construction features an electrostatically charged, pleated design that blocks & attracts harmful airborne particles.  Durable commercial grade beverage board frames with dual side support and wire backings outperform standard cardboard designs.