All of the classic DB Aston Martins from DB2 through DB6 have a battery master switch. The original Lucas switches have been unavailable for years so replacing these units has become a problem. There are some Far East reproductions out there but they are absolutely terrible. We have had them come apart inside after a few turns. We have had others that have so much resistance that the starter motor will not operate. In any case, more than one car has been left by the side of the road because of this. As a solution, the factory has come out with this neat replacement. They have taken a modern heavy duty master switch and attached a mounting plate so that it is a direct bolt-in replacement. They have also made a knob that looks like the original. The only real difference is that "Off" is now counter-clockwise instead of clockwise as original. A neat and permanent solution to an ongoing problem.