The Akrapovic muffler with db killer comply with the European regulations on noise emissions. thanks to the use of a new special wool sound absorbing combined with a small device located at the end of the db-killer fondello.All 'internal muffler is built as a racing silencer. a db-killer (very simple operation. it comes to unscrew a bolt) muffler behaves exactly like a silencer racing.Naturalmente after this operation, the muffler will be used only in closed circuit and no more road open to traffic,In fact, the removal of the bolt will invalidate the approval. db killer can be refitted using the same bolt. back within noise limits prescribed by law although no longer approved.