Optional Specifications Optional Diamond Grit 6#, 16#, 36#, 60#, 80#, 120#, 180#, 220# Optional Metal Bond extremely soft, very soft, soft, medium soft, hard, and very hard Optional Packaging 6 or 9 pieces per box Optional Painting Color High light or Matt, common colors are: orange, yellow, red, black, purple and blue Other services OEM/ODM service is available, such as logo engraving(free), painting color(free), and etc. Knowledge About Concrete, Bond, and Grit  Concrete: The concrete can be soft, hard, abrasive, dusty and brittle, etc. There are no two concrete floors ever the same. Typically the concrete will be more abrasive when it is new or has a high concentration of sharp sand. The rougher of the concrete floor, the harder of the bond you need, to get the best performance of the diamonds. Bond: The metal binder that holds the diamond grit in the segment. Typically the harder of the bond, the longer lifespan of the concrete grinding tools. Hard bond is used for soft concrete, the medium-hard bond is used for medium concrete, and soft bond is used for hard concrete. Grit: One of the measurement units used for the diamond particle size in the segment. The smaller of the diamond grit number, the bigger of the diamond particles. Typically the smaller of the diamond grit number, the more aggressive of the segment. So, the small diamond grit is usually used for coarse/medium grinding, while the large diamond grit is usually used for fine grinding or polishing.SYF-A34SYF-A21