The FORIS windows are designed in such a way that they can act as burglary-proof protection. It is why a purposefully shaped steel reinforcement can be installed in the window frame in order to accept actual brackets of burglary-proof operators. One has to remember that application of burglary-proof operators needs compulsory installation of a window handle with a keylock or a locking button, not to mention about he glass panels that must be of adequate burglary-proof grade.