charlie27, I can't see down inside the muffler. but just looking at the short length, and if I had to guess, I think the sound exits through the muffler without much of a baffling. It's just my opinion. Maybe some of the other people could talk to you about the muffler. I'm sorry about your loosing your original thought for this thread. If you are a new guy, welcome to the forum!
I was offered this and another style by my dealer when there was a delay on the Yoshi slip on and personally didn't like it,looked cheap.Still happy with my Yoshi the more ks I get on the bike the better it is starting to sound,plus I was worried that such a short pipe would place too much heat onto the rear tyre.