BUYTUS 180mm 7 Inch Diamond Wet Polishing Pads for Granite Marble Concrete Stone Grinding Wheel Sanding Disc Abrasive Polish Tools(1 Pc-7 Inches,50). Diameter: 180mm/7inch ; thickness 4.2mm ; bore: 20mm ;GRIT: #30 #50 #100 #150 #300 #500 #800 #1000 #2000 #3000 ;quantity :1/2 pcs. Suitable for concrete granite marble engineer stone. recommend 3500 - 8500 rpm (grinder or polisher speed must be lower than 8500 RPM). Sharp, wear-resistant and high efficiency, good polishing results without any color left on stone. Easy to use,Good Performance and long lifeand new and high quality. Farbe:1 Pc-7 Inches