Manufacture and sale of equipment to prevent the theft of equipment. Security equipment and theft prevention devices for site machinery and farming equipment. Anti-theft devices through electromechanical immobilisation using a tamper-resistant coded security valve. Electromechanical anti-theft devices, immobilisation of vehicle by disconnecting fuel supply. Electronic starter-prevention device using key reader or standard keyboard against the risks of deterioration and unauthorised use of equipment. Tracking, monitoring and control.