Two material components for even more expansion volume and optimum load values in solid and perforated construction materials. Intelligent, self-activating functions depending on the substrate. For a wide range of applications. Best possible feedback from the anchor. You can feel when the anchor is perfectly seated. No annoying twisting of the plug during installation thanks to the distinctive anti-twist protection. The smooth-running opening enables the screw to be inserted easily and securely guided and fixed in the screw channel. The long versions offer additional "bite" in problematic building materials.