Perfect for: Gunsmiths of all skill ranges. Gun owners who are looking to do more detailed work. Gun enthusiasts who are looking to work on all types of guns. Specs: Diameter: 3 3/4". Thickness: 1 ¼ Directions for Using the Magnet: The magnet is on the interior edge of the Smart Bench Block. After you punch a pin, lightly move the block around on your work surface to ensure that the pin contacts the magnetized edge. The Universal Smart Bench Block is a tool that any gun owner looking to do minor to major work on their firearm will be happy to have. Made from engineering-grade resin, this block won?t mar or damage your favorite guns and the outside rubber liner keeps the block from sliding on any surface when driving pins. And inside the block is a magnet that grabs dropped pins. So intelligently designed, you?ll feel smarter just using it..