Bikemaster Air Filter Yamaha Yzf-R1 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 with the BMC air filters scored an impressive 97,5 filtration efficiency at Iso5011 test. Features: Triple-layer protection Corrosion-resistant Environmentally Friendly Washable and reusable Will last a lifetime of your motorcycle with proper care