This is a single fired 50 caliber bullet brass cartridge that has been adapted into a Pen. The wood is a black walnut and African Zebra Wood. This is a great gift for a big game hunter, friends and family in the military. Customize your pen for the geographical region that the person served in. Afghanistan has Oak, Walnut, Ash trees. Vietnam has a lot of Mahogany woods and Iraq has Olive Trees. If you would like to customize your 50 Caliber Pen please see the shop page to see how to request a custom order.