Heat exchangers of 25 & 30 H.P. engines have been the first attempt of Volkswagen to heat the engine block as well as the interior. Heat exchangers recover the warmth through exhaust tips and just these exhaust parts are very susceptible to corrosion caused by changes in temperature and influences of exhaust gas. For a long time BBT has these tubes to repair the heat exchangers in its range, though in the past one had to recycle the connecting flanges of the old exhaust tips. From now on we have an improved and more complete product available. Tubes are sold a pair, inclusive the flanges that you've still got to weld.