This Cork Borer Set comes with 12 different sizes of borers. The pieces are stackable and made from nickel-plated brass. The set also includes a cleaning rod, and each borer has individual handles. The outside diameter sizes for the cork borer set range from 4.8mm to 21mm. The set includes the following individual sizes: 4.8mm, 6.4mm, 8.1mm, 9.7mm, 11.2mm, 12.6mm, 14mm, 15.5mm, 16.8mm, 18.2mm, 19.6mm, and 21mm. The ends of the cork borer set have been sharpened, but they will require re-sharpening after use.