Sterling Seal DM-FI5257310204 Purolator Defiant Mark 80-D Extended Surface Pleated Air Filter, Mechanical Merv: 8, 20" W x 25" H x 1" D (Pack of 12) Mechanical MERV8 Filter Exceeds ASHRAE Standard 62 air cleaning specifications for filters installed upstream of cooling coils; Air Flow Capacity listed at 300FPM Low initial resistance for energy savings; Quality Engineered; Consistently Produced; Made of 100% synthetic Fibers; Made in the USA for over 30 years Two-Piece Frame Construction: will not rack, warp, or bend under normal handling or operating condition