Diablo, 4.5" x 1/4" x 7/8", Type 27, Premium Masonry Grinding Discs, Provides Superior Performance & Increased Productivity, Premium Aluminum Oxide Blend, Grind Through Material Faster Than Other Discs & Extra Long Grinding Life, Fully Reinforced For Use In Hand Held Cut-Off Work, Ideal For Use When Working In Hard To Reach Areas.