These are the 3 1/2" Rineharts and I think they look and sound great. I bought them from Cycle Solutions and a week after I bought them they showed the 4" slip-ons (which have the indents) on their web site for $20 more, oh well. We ran about 176 miles today and got 40.5 mpg with the stage 1 setup. I am okay with that, seems in the ballpark to me, although that mileage might have been better if I didn't whack the throttle every time we went under a bridge.