Yeah, I tried the four inch for the deeper sound. I still believe bigger diameter gives a deeper tone. Plus, I like the look of 4" mufflers on a bagger. The website has a good picture of what the inside and baffle looks like. I am sure the baffles come out if you take the end cap off like the Riney's, but no baffle sounds horrible and no back pressure means no performance. I am going on a 300 mile trip tomorrow. I will see how these run and perform.

 

Woof woof, bow wow

 

Till I saw this post, I didn't know what slip on's I had, I bought the 2009 SG with 3000 miles on it and after 12 months I have 8000 on it. They sound good to me, not to loud and not any bluing, though I have seen some like mine on another bike that is bluing....
http://i1070.photobucket.com/albums/...817_170232.jpg

 

Da one on the right can be pumped up with HD air pump, same valve stem and everything.....

 

I ordered them last night, will see how they do. Will make a report