The Carl Kammerling 424003 Hole Saw is a professional cutting tool designed to create clean, smooth holes in aluminum, wood, metal, brass, steel, and cast iron materials. The hole saw has a 20mm diameter and is ideal for construction, renovation, and maintenance projects. It is reliable, tough, and designed to last with durable construction and a high-quality, heat-treated cutting edge. This hole saw is a perfect choice for those looking for a professional, high-quality tool for their projects.