This is a pen made from a .50 Caliber casing like the ones they use in the military. This end of this pen is made with a burl dyed green. This comes with a pen case that looks like a tactical gun case where one stores a rifle or bow. The pen cases come in green or black- please specify or it will be black. The ink is a cross refill that can be bought at any Staples, Office Max, or Amazon. The one currently in the pen is black.