The fischer DUOPOWER offers very good hold values as a result of its 2 components: Depending on the building material, the grey components made from high quality nylon automatically activates the optimum product function (expansion, folding, knotting) for the best hold. The expansion wings of the red component support the secure expansion and offer additional security to the grey component. Easy screwing-in of the screw and correct "tightening" to close. No over-tightening of the screw. The preshaped edge on the plug head prevents the plug from slipping into the drill hole. The screws provided are optimally suited to the fischer expansion plug Duopower.