Just an FYI for those of you who might see this thread and jump on the train. I ordered my DR.D NS-4 spark arrestor from Motorsport.com. I ordered the wrong one. Don’t buy DR.D Part no 2709. I still made it “work”. However, none of the mods in this thread are truly spark arresting, since the holes on the side of the stinger pipe aren’t blocked by mesh. Time will tell if I made a poor monetary descision here.