Twin Air Foam Air Filter 155510FR HolidayGiftGuide Racing Sealed bearings are abec RCB CA X3 Racing Sealed bearings are abec and iso 9002 rated and include a matched set of plated washers that protect and reinforce the outside bearing seals from damage and wear The new patented lightweight and highly ventilated double wall knee cup system offers strong impact force dispersion and absorption whilst ensuring maximum coverage area in all riding positions greaseless sealing ring ensures maximum contact with your airbox while acting as a breathable gasket for increased air passage Coarse open pore foam catches airborn dirt Fine open pore inner foam acts as second filter to trap the smallest particles while ensuring maximum air passage