Grits: #50,#100,#200,#400,#800,#1500,#3000,(Coarse to Fine, 1 piece each grit size ) Package: 7PCS/lot Workable Thickness: 2mm Material : diamond and resin/ Aluninum Size: Diameter 25 mm, M14 standard mounting thread (Please inform us if you want 5/8-11 ) Feature: Use wet only Maximum speed 4500 RPM Designed for wet polishing with water feeding holes Comes with 7 pieces including 50, 100, 200, 400, 800, 1500 and 3000 grit the good quality product Does not change in the color of the stone itself, with glazing fast, good brightness and not fade. User manual: Use them from coarse to fine, the final polishing. The whole process takes water to cool fully, but in the polishing stage,water should not be too much.