Guess I'll have to take a closer look. I've looked down the openings in the box before, but doesn't look like there's a mesh screen of any type down there. Spark arrestors are required in most places here in the States if you ride off road. Bad news if you get caught riding off road without one where required. Suppose I could fabricate my own. Ah, the trials and tribulations of owning a Ducati! LOL