The part fit my 2005 YZ450F with no issues. I purchased the quiet insert with it. I needed a spark arrestor to qualify for hairscrambles in Florida. I failed the noise check with both the regular screen and quiet insert. My stock silencer has very few hours and packing looked almost new. I am going to try stuffing more packing in and see if I can pass next time. I will be disappointed if I have to buy another whole silencer after purchasing this product. The bike sounded the same as stock with the regular screen and power was good. For someone not worried about decibels, it is a good product.