A selective Global Service Redirection mechanism allows a service provider, for instance, to instruct only CDMA2000 mobiles to access specific carrier that is deployed to support advanced services known as 3G services. The system enables a participant to re-delegate the authority to another participant by an authorization certificate. The feedback circuit receives a feedback signal indicative of the electrical condition of said first current regulator. A non conductive support bar disposed at least partially within the plug body separating at least portions of the first contact and the first conductor from the second contact and the second conductor. To resolve this problem, it is proposed that the cuvette member is mounted by means of a cuvette bearing and the filling and the emptying device are fastened exclusively to the cuvette in such a way that the position of the cuvette relative to the surroundings thereof is determined and defined exclusively by the cuvette bearing.