You should buy this AC1. Motorcycle exhaust pipes are fitted with silencers at the end to reduce the noise from the engine. The silencer attached at the end of the exhaust pipes causes the gases to expand so that any noise is expelled.
Lextek Stainless Steel AC1 Classic Silencer 350mm 51mm
Lextek Stainless Steel AC1 2 x Polished 350mm Exhaust Silencer Slip-on Black
Lextek Stainless Steel AC1 Polished 350mm Exhaust System Silencer Silver Scooter
Lextek Stainless Steel AC1 Polished 350mm Exhaust System Silencer Black Rear
Lextek Stainless Steel AC1 Polished 350mm Exhaust System Silencer Chrome Rear