Sea Pearls uncoated lead dive weights are die-cast from lead that has been reclaimed from car batteries. However, lead in its raw form does not meet the standard for Sea Pearl&';s dive weights, so we add other elements like antimony and tin to derive the alloy required for proper hardness and appearance. Using immense pressure, the molten lead alloy is injected into multi-cavity molds. This process provides the best quality, most consistent weights in the industry. Weight belt webbing laces thru the weight Hardened with antimony to prevent deforming Great for use with nylon or rubber weight belts Ideal for use in weight-integrated BCs Rounded and contoured for comfort