Injen 8-Layer Oiled Cotton Gauze Air Filter 4.0in ID/ 6.5inBase / 6.75in Height / 5in TopWith 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