15 x 5 inches. The Diamabrush™ Mastic Removal Tool is formulated to remove stubborn coatings fromconcrete such as mastic, carpet or tile adhesive, or thin-set and thin mil coatings likeurethane and paint. Diamond-coated blades grind tough coatings away. Mounts to anystandard floor buffer or auto scrubber. Replacement blade kits available. Counter-clocksmart rotation.