A blackjack weapon or sap refers to a group of weapons that are short, concealable, and weighted (usually filled with lead powder, molded lead clay, or lead shot) to constitute an effective bludgeoning device. When filled with loose change, the weight of the sap is increased significantly (up to 8 ounces), allowing it to strike with authority if used as a self-defense weapon. Note: Not a blackjack weapon, but a sap.