It's just a cool metal screen that the US Forest Service has decided stops sparks from exiting the exhaust and starting massive wildfires. To me the idea seems pretty preposterous, but it's the law, so what can you do.

it arrests and prosecutes the spark if it tries to escape.........

ah, ok. so its a necessity.
thought maybe it changed the sound or something.
damn laws eh

best definition. a+

When I lived up in WA still, there was a kid who apparently went riding out in the woods without a spark arrestor, and somehow said forest caught on fire. Well the USFS determined that it was a spark from a dirt bike that started the fire (how they did that I'll never know) and so they ended up tracking this kid down and once they found a bike with no SA, they put the blame for the fire on him. With the blame came the bill for the fire which was millions of dollars.

like he is really going to be able to pay that.......

That was my thought too. Who knows what they ended up working out. I'm guessing he wasn't getting any federal aid for college though after that, lol.

aaron is my bitch