High-torque exhaust in a subtle design. Provides considerably more top speed. E-certified. For those who need a new exhaust and want more power but do not want to ride with a small and particularly sporty sounding exhaust on their scooter. very good torque curve and excellent performance on 50cc and 70cc Sports cylinder. This Tecnigas Silent Pro exhaust system fits all CPI from 2003, Generic, Keeway, MaWi 2-stroke, Longjia and vehicles with Chinese 2-stroke Minarelli based engines Note. If the exhaust is supplied restricted, it can easily be used as a standard replacement item . The restrictor is welded into the exhaust manifold. Removal of the restrictor increases performance, but negates the general operating permit (ABE).