High performance DNA air filter. Features Inlet diameter: 51 mm Drawing: Hexagonal Length: 86 mm Outer Diameter Large: This filter has a special Hexagonal design with smaller outer dimensions 101 x 76 mm Outer Diameter Small: This filter has a special Hexagonal design with external dimensions 81 x 58 mm Flange: 16 mm Top Style: CNC pressed aluminum Click on the window in the other (instructions) to see the technical characteristics