Manufactured by Factory Spec Pleated element style for more air flow which translates into more power and acceleration Washable and re-usable Filter must be oiled before use ID is 4 3/8" Fits the Yamaha ATV models listed below: (You will need an adapter for most air boxes) 2004 Yamaha YFZ450 2005 Yamaha YFZ450 2006 Yamaha YFZ450 2007 Yamaha YFZ450 2008 Yamaha YFZ450 2009 Yamaha YFZ450