Pearl Abrasive P4 V450M Crack-Chaser Blade 4-1/2 x 5/8-11Pearl Abrasive P4 V450M Crack Chaser Blade 4 1 2 x 5 8 11. NON RETURNABLE ITEM For cleaning, routing, and repairing of cracks in cocrete and most other building materials Diamond matrix is designed for consisted, even wear Produces 1 2" wide 70Degree V shaped groove Direct Sintering Technology Dry Cutting Pearl Crack Chaser Diamond Blades for Cleaning, Routing and Repairing of Cracks in Concrete and most other building materials 100% GE Diamond Matrix