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 YZ250F 2019-2021 YZ250FSP 2021 YZ450F 2018-2021 YZ450FSP 2021