It comes with the quiet insert/SA, also known as "the potato" cuz it's as restrictive as shoving a potato up your exhaust. You'll want to pull that insert ASAP. If you need a spark arrestor to ride forest service roads etc, you can purchase one separately from Yosh for about $15. That's what I did. It's just a small half-dome screen thingy that goes in the end cap in place of the potato insert. It's not restrictive.