The Runyon Surface Prep 7″ Non-Threaded 10 Segment Arrow Concrete Grinding Cup Wheel is designed for aggressive grinding of concrete, glue, and light coating removal. Arrow shaped segments pierce light coatings and minimizes gumming up of segments. Arrow cup wheels have angled segments that are designed to help get underneath light coatings and prep concrete in a single step. They are also used to aggressively grind bare concrete and remove high spots. The cup wheel works great on bare concrete as well and the extra tall diamond segment offers a longer tool life.