Those of you whom are considering or "on the fence" about the 4" Rineharts should definitely pull the trigger on these puppies! I just added them to my 2011 FLHXSE2 and man are they sweet! I have never heard a pipe sound better than these! They have a deep, DEEEP, bass-like throatiness that I can only compare to a race car. I had Rinehart True Duals on my 08 Road King and loved them, but they pale in comparison to the sound of these 4". I combined them with the FULLSAC X-PIPE (and SERT) and I'm completely blown away by the increase in power and performance. There are deals out there as these posts have shown, but they are on back order in alot of places. I have yet to see anyone else running these too, so everyone is amazed that I'm putting over 125 ft lbs of torque to the rear, as well as the wonderful sound from Rineharts. Pull the trigger and be amazed, trust me, I was!