Large Bore Exhaust System (Twin Box) in stainless steel. 2 Piece System EXCLUDING Downpipe. This exhaust is useful when fitting 1275cc/1300 engines. It can also be fitted to 948/1098 engines using an appropriate manifold. Internal diameter 1.5 inch.This exhaust system requires the use of a suitable downpipe to connect to Marina or Ital exhaust manifolds. Alternatively use EXH150 LCB manifold in place of manifold and downpipe to connect between cylinder head and exhaust.