K&N Engineering first offered cold air intake systems in 1987s. The original intakes were made of molded plastic intake tubes and a conical, cotton gauze air filter. In the late 1990s quite a few aftermarket manufacturers entered the market place such as Injen, AEM, Airaid, True Flow, AFE and Volant to name a few. In addition many manufacturers imported their designs from Japan and Korea lending to the popularity of the Japan domestic market (JDM) air intakes in sport compact markets. K&N and many of the other intake companies now offer metal tube design intake systems, allowing a greater degree of performance. 
K&N HIGH FLOW COLD AIR INTAKE FILTER, RED -- Racing use only; Not applicable nor intended for use on emission controlled street or highway vehicles; 96 to 99 percent filtration efficiency; 8 in. height, 7.5 in. base outside diameter, 6 in. flange inside diameter, 1 in. flange length, 5 in. top outside diameter; Oiled element; Round tapered style; Chrome metal end cap; Made of multiple interwoven layers of surgical cotton gauze; Increases horsepower and acceleration while providing excellent filtration; Constructed with ultra-strong molded pliable rubber flanges which absorb vibration; Allows secure attachment; Can be stretched up to 0.0625 in. or 1.5 mm to fit in-between sizes; Washable and reusable; With K&N's limited million mile warranty.
Material: Cotton gauze
Style: Conical
Type: High flow
Warranty: K&N's limited million-mile warranty
Part #: K33RF1020
K&N HIGH FLOW COLD AIR INTAKE FILTER, RED -- Racing use only; Not applicable nor intended for use on emission controlled street or highway vehicles; 96 to 99 percent filtration efficiency; 6 in. height, 7.5 in. base outside diameter, 6 in. flange inside diameter, 0.63 in. flange length, 4.5 in. top outside diameter; Oiled element; Round tapered style; Chrome metal end cap; Made of multiple interwoven layers of surgical cotton gauze; Increases horsepower and acceleration while providing excellent filtration; Constructed with ultra-strong molded pliable rubber flanges which absorb vibration; Allows secure attachment; Can be stretched up to 0.0625 in. or 1.5 mm to fit in-between sizes; Washable and reusable; With K&N's limited million mile warranty.
Material: Cotton gauze
Style: Conical
Type: High flow
Warranty: K&N's limited million-mile warranty
Part #: K33RF1048
K&N HIGH FLOW COLD AIR INTAKE FILTER, RED -- Racing use only; Not applicable nor intended for use on emission controlled street or highway vehicles; 96 to 99 percent filtration efficiency; 6.5 in. height, 7.5 in. base outside diameter, 6 in. flange inside diameter, 1 in. flange length, 5 in. top outside diameter; Oiled element; Round tapered style; Chrome metal end cap; Made of multiple interwoven layers of surgical cotton gauze; Increases horsepower and acceleration while providing excellent filtration; Constructed with ultra-strong molded pliable rubber flanges which absorb vibration; Allows secure attachment; Can be stretched up to 0.0625 in. or 1.5 mm to fit in-between sizes; Washable and reusable; With K&N's limited million mile warranty.
Material: Cotton gauze
Style: Conical
Type: High flow
Warranty: K&N's limited million-mile warranty
Part #: K33RF1042
K&N HIGH FLOW COLD AIR INTAKE FILTER, RED -- Racing use only; Not applicable nor intended for use on emission controlled street or highway vehicles; 96 to 99 percent filtration efficiency; 6.5 in. height, 6 in. base outside diameter, 3 in. flange inside diameter, 1.88 in. flange length, 5 in. top outside diameter; Oiled element; Round tapered style; Black rubber end cap; Made of multiple interwoven layers of surgical cotton gauze; Increases horsepower and acceleration while providing excellent filtration; Constructed with ultra-strong molded pliable rubber flanges which absorb vibration; Allows secure attachment; Can be stretched up to 0.0625 in. or 1.5 mm to fit in-between sizes; Washable and reusable; With K&N's limited million mile warranty.
Type: High flow
Part #: K33RU4730
2000 SERIES HIGH FLOW COLD AIR INTAKE REPLACEMENT FILTER -- A High-Flow Replacement Air Filter For The 2000 Series Cold Air Intakes, Features 4 Layer Cotton Gauze Material And Strong Molded Rubber, Washable And Reusable
Type: Clearance
Part #: KV430102