BMC Air Filters offer better air flow to the engine: The cotton gauze BMC uses has larger links, allowing a better air flow, but using several layers of oil soaked cotton allows to block any impurity larger than 7 microns. Greater retention and screening: BMC air filters scored an impressive 97,5% filtration efficiency at ISO5011 test. Wider filtering area Maximum air permeability and higher air flow passage. The choice of champions: BMC equips some of the most important teams in Formula 1, MotoGP, World Superbike