Anetic Aid's AT4 Tourniquet System is a completely new design which is intuitive and simple to use. Its compact construction is light weight yet robust, containing advanced technology which offers maximum safety and reliability. The electronic version operates from its own integral air supply, removing the need for an external pressure source, and both this and the pneumativ versions have sensitive leak compensation facilities as well as automatic self-diagnostic checks on start-up, which means they are calibrated every time they are switched on. An innovative added safety feature has been incorporated for Bier's block regional anaesthesia procedures (IVRA): it will simply not be possible to deflate cuffs in the wrong order risking the dangerous release of anaesthetic into the rest of the patients body.