Feature: 1. WITH AIR HOLES: The concrete grinding wheel has air holes to help maintain and cool the cutting pattern and reduce wear. 2. MADE OF DIAMOND: Made of excellent diamond material, has high hardness and wear resistance, with efficient grinding. 3. APPLICABLE MATERIALS: Can be used for polishing and grinding granite, cement, marble, rock, masonry, concrete, etc. 4. LARGE SEGMENT: The diamond cup grinding wheel has large grinding segments and heat treated steel body to increase durability. 5. 12 TEETH DESIGN: With 12 segment teeth design, can be dry and wet grinding, and processing uneven surface. Specification: Item Type: 4in Concrete Grinding Wheel Material: Diamond Application: Used for polishing granite, cement, marble, rock, masonry, concrete Color: Yellow Number of Teeth: 12 teeth Product Outer Diameter: Approx. 100mm / 4in Product Inner Diameter: Approx. 20mm / 0.8in Applicable Inner Diameter: Approx. 16mm / 0.6in (Use Gasket). Package List: 1 x Concrete Grinding Wheel1 x Gasket