Metal Worx Nipple Clamps. Give precious metals a whole new meaning with these heavy weight nipple clamps. Cast in high quality steel and hand polished to perfection. Each Metal Worx masterpiece comes in a discreet storage case you can use to store your toy after use. Features: high quality polished steel. Barrel adjusts for comfort. Adjustable weight for extra pleasure. Soft rubber liners. Eco-friendly and nickel-free. Materials: Steel, Rubber. Country of origin China.