Our Pro-Pleat MERV 8 pleated panel filters are rated according to ASHRAE 52.2 standards and 40% to 45% efficient according to ASHRAE 52.1 standards. Pro-Pleat filters are made with electrostatically charged synthetic media that is bonded to a rust inhibitor coated expanded metal. The entire inner surface of the 24 point beverage board frame is coated with adhesive to encapsulate the pleated media pack, prevent air bypass, and provide rigidity. Our synthetic media does not support microbial growth. Available in standard and non-standard sizes, in 1", 2" and 4" depths. Custom sizing available, please contact your nearest branch location.