Chrome plated mild steel with steel wool type internal baffle material these are made in the midlands in the same way that they have been since the 1950's or even before. Only genuine Norman Hyde Toga silencers can give the authentic Triumph sound. With the under-body catalytic converter in place the sound is not as loud as the previous generation twins but still gives a nice deep sound. Can be used without any further mapping to give gains of just under 2bhp. With a custom map or Power Commander greater gains would be achieved. Weight saving of approx 1kg over standard