Replacement fuel cutoff switch for SPI models. Can also be fitted to MPI models however it is not the direct replacement. The inertia switch shuts of the fuel supply in the event of a collision to prevent fuel leakage or fires. If you ever go over a large bump and you injection Mini dies, check this switch as they can get very sensitive. It is located on the firewall on the LH side of the engine just behind the radiator next to the bonnet hinge. The button must be depressed for the fuel pump to operate.