This 3 piece tool holder with ribbed and nickel plated brass hilt offers optimal user friendliness with its rotatable hand support and the screw head the 2 hardened double sided collets offer the following clamping ranges clamp 1 01 11 mm diameter 20 25 mm diameter clamp 2 10 20 mm diameter 25 32 mm diameter ideal for clamping all precision mechanics drills as well as grinding and cutting discs