Using only the best flame-laminated dual-layer foam bonded with the highest quality glue No-Toil handmakes each foam filter to stand up to the roughest and toughest of any style of riding or terrain. Note: No-Toil air filters oil washes clean in water and is 100% biodegradable; dirty water can be thrown down the sink. You do not need to use harmful petrol or kerosene to clean your filter. No Toil oil is 100% waterproof - until water is mixed with No Toil cleaning crystals). Fits: Yamaha WR250 Z 3RB 1991-1993 WR250 Z 4JW 1994-1997 WR250F 2001-2002 WR400F 1998-2000 WR426F 2001-2002 YZ125 1989-1992 1994-2009 2011-2020 YZ125X 2020-2021 YZ250 1988-1996 1998-2008 2011-2015 2017-2020 YZ250F 2001-2007 2009 2011-2013 YZ400F 1998-1999 YZ426F 2000-2002 YZ450F 2003-2007 2009