Many off-road areas now require some form of a spark arrestor to limit the chance of fires. EMPI now has a variety of spark arrestor assemblies to choose from. The 3" & 4" disc kits are for clamp on or weld on installation. The 10" & 17" mufflers are Stainless Steel outer shells with 4" discs for fine tuning of your exhaust restriction. All of the assemblies come with long enough screws to add additional discs if your horsepower needs dictate it. The 10" muffler is also available with & without a mounting bracket so you can custom fit it to an existing exhaust system if you so choose.