Apollo Horticulture 4&rdquo; Inch Premium Carbon Charcoal Air Filter Scrubber 1 - 4 Apollo Horticulture Premium Carbon Air Filter Air Flow  200 CFM / Dimensions: 8" x 13.75" with 4 Flange Ducting RC 48 Virgin Activated Carbon / Cap Construction for Maximum Output 50mm Carbon Layer of Thickness for Higher Absorption and Performance Package Includes: 1  4 Carbon Filter / 1  Pre Filter