The fischer DuoPower offers very good holding values thanks to 2 components: The grey component made of high-quality nylon automatically activates the optimum functional principle (spreading, folding, knotting) for the best hold, depending on the building material. The expansion wings of the red component support secure spreading and offer additional security to the grey component. Easy screwing in of the screw and correct "pulling" at the end. No over-tightening of the screw. The moulded edge on the plug head prevents the plug from slipping into the drill hole. The screws supplied are optimally matched to the fischer DuoPower expansion plug.