BULLHEADS Self-Defense Key Chain, Color: Mexican Flag BULLHEADS brand self-defense key chains are constructed from rugged cold-rolled steel plate. BULLHEADS are a highly effective and attractive self-defense tool, which can be used by women and men in environments where handguns, stun guns or other self-defense tools are inconvenient or prohibited. BULLHEADS are a unique conversation piece and come in a variety of colors and coatings.