The Bulletproof Caliber Chalker is a uniquely original and innovative design. Machined from a solid block of lightweight 6061 aluminum it has nickel, dime, and penny radius shapers machined into its surface and hard anodized for durability. This is the only tool available anywhere that offers a penny radius shaper. The machined diamond teeth will stay sharp for years and years. Also incorporated into this tool is a flat “Tapper / Scuffer” with a machined pattern to give your tip the perfect texture to hold chalk and grip better than any other tool on the market!