Since 1969 K&N Engineering has been designing, manufacturing, and enhancing High-Flow Air Filters for the motorcycle enthusiast. K&N invented the High-Flow category and the High-Flow Technology that supports it. K&N have hit the sweet spot ? an optimal blend of high air flow, filtration efficiency, durability and dust capacity. A K&N Air Filter is made of 4 to 6 layers of cotton gauze sandwiched between two epoxy-coated aluminium wire screens. The cotton is treated with a specially formulated grade of oil causing tackiness throughout the cotton?s microscopic strands. The nature of the cotton allows high volumes of airflow, and when combined with the tackiness of the oil creates a powerful filtering media that ensures engine protection!