The edge of the blade is segmented to cut faster than a continuous edge. These blades have diamond grit that lasts up to three times longer than the grit on other blades for masonry and stone in continuous use applications on hard, abrasive materials. Use dry or with water or coolant (not included). Blades come with a reducer bushing to adjust the arbor diameter. For blades with a round/diamond arbor, detach the center piece to expose the diamond shape.