I also would go for the EU-3 Akra...Best materials as also build quality and DB-killers for deep throaty boxersound easily removeable ! Next choice would be the Akra EU-4 "fishcan" where the CF endpiece is easily taken off with 2 bolts and not a bunch of rivets have to be drilled out in order to to get to the bolts to be grind off to remove the DB-killers to make the bike sound like a proper motorcycle...Spend the extra money on the Akra...Best quality/best product out there ! The other stuff doesn't sound as throaty,doesn't give additional mid-range torque and does not last as long...