Slip-Ons represent the first step in the exhaust system tuning process, and they offer a great balance between price and performance. Change the nature of your bike by adding more power, improved performance, and the unique Akrapovič sound. Everything packed in stylishly designed Slip-On exhaust systems. The result of taking design very seriously is a beautifully crafted exhaust system.The muffler outer sleeve is made of titanium.