The traditional wedge design is German-made in light-weight magnesium and available in single- or double-hole models. The double-hole wedge is ideal for all pencils in the artist s sketch box including large diameter art pencils. The small hole (7.8mm) is for a standard pencil diameter and point taper. The large hole (11 mm) is perfect for careful sharpening of charcoal, pastels and colored pencils. To assure a good cut, blades should be changed often.