... sq. ft per cut.2. Designed for effective, efficient grinding wheels on concrete.3. Available diameters: 3, 4, 5, 7inches.4 ... etc.5. Use by wet and dry. Item No.DiameterGritThicknessBackUsageDiamond griding head3", 4", 5", (80mm, 100mm, 125mm,) #50, #100, #200, #400 ...