Optional available headers from the finest stainless steel offer an upgrade to a full system when used with the Akrapovi? Slip-On exhaust system. Let your bike stand out with more power, beautiful design, and the unique Akrapovi? sound.EC/ECE type approved, with integrated catalytic converter. Featuring exhaust valve for improved rideability in lower rpm.Optional headers fit also with Akrapovi? standard (first fit) / BMW accessory Akrapovi? silencer.