Magsafe 786-300 is used which will be controlled by a relay. The key design element was to lock door using magnetic force rather than by mechanical means. It now offers the ability to monitor upto 2 magnets from a single low cost (DIN Rail Mount) Control Unit or the system can be extended by connecting Extender Modules (DIN rail mount) to allow for upto 8 monitored magnets on one system. It incorporates a number of innovative designs including: