Akrapovic Yamaha R1 Slip-On Exhaust 2009. Our sporty and lightweight SLIP-ON system offers a great balance between price and performance, and represents the first step in the exhaust system tuning process. The change will also be visual as our HEXAGONAL mufflers fit the exterior line of the R1 perfectly and add a clean racing image. The muffler outer sleeve is made of titanium or carbon fiber, which gives a special hi-tech touch to our SLIP-ON system. We offer an optional Y type link pipe made of conical titanium tubes for more power and torque. You will also save up to 4.13 kg, compared to using a stock system.