A "Knuckle Duster," also known as a brass knuckle, is a type of weapon designed to fit over the knuckles of a person's hand. It is typically made of metal or plastic and is used to enhance the impact of a punch. The design allows the user to deliver more forceful blows while protecting their fingers. These weapons are often associated with street fighting and self-defense, but they are illegal in many places due to their potential for causing serious injury. Laws regarding the possession and use of knuckle dusters vary by region, making it important to understand local regulations.