DUX 3-Way Adjustable Magnesium Pencil Sharpener w/ 3 Replacement Blades. 1422N DUX 3-Way Adjustable Magnesium Pencil Sharpener. 3 pack Spare Blade for DUX Handheld Sharpeners, Turn the knurled adjustment knob to one of 3 positions to achieve a blunt, regular or very sharp point.