The fischer DUOPOWER offers very good holding values due to 2 components: The grey component made of high-quality polyamide automatically activates the optimum functional principle (spreading, flaps, knots) depending on the building material for the best hold. The expansion wings of the red component support secure spreading and provide additional safety to the gray component. Easy screwing in of the screw and correct "pulling" at the end. No overtightening of the screw. Rim molded to the anchor head prevents the anchor from slipping into the hole. The screws with panhead supplied are optimally matched to the fischer Duopower expansion anchor.