Injen High Performance Air Filter: 5 inch: K Series Parts Injen High Performance Air Filter 4.50 Black Filter 6.75 Base 5 Injen High Performance Air Filter 5 Black Filter 6 1 2 Base 8 Tall Injen High Performance Air Filter 2.75 Black Filter 5 Base 5 Tall. With a rich history in racing and the street performance, Injen Technology has proven itself as a leader in filtration engineering and technology. Lab tested and race proven, Injen? s air filter line features state of the art designs and performance. All of Injen? s 8 layer cotton gauze oiled air filters feature a tightly layered media that is specified for our use, along with a proprietary filter oil that includes highly advanced tackifiers to stop as much dirt and contaminants as possible. This allows our 8 layer oiled cotton gauze air filters to flow the maximum amount of air, all while protecting your valuable engine from harmful dirt and debris. 100% cleanable with the use of our Pro Tech air filter cleaning kit ? part number X 1030. Order yours today!