12 Piece SetSize: 6" Width X 12" LongThickness: 1 Each Of .001", .0015", .002", .003", .004", .005", .006", .007", .008", .010", .012" And .015"Material: BrassShims Are Generally Used To Fill Gaps, Act As A Barrier To Prevent Wear, Used To Level And/Or Support Or Adjust For A Better FitUsed When Some Stiffness Is Required And Where Corrosion Problems Exist