Note: This product is made of aluminum alloy material with steel balls that have undergone shock light treatment. The surface may have silver metal powder and ink. Before use, rinse with water. Aluminum alloy has high metal activity and should not be soaked in salt water or water above 60 degrees Celsius, as well as detergents, especially dishwashers. Otherwise, it will oxidize and turn black. Daily maintenance requires rinsing with cold water and wiping with a cloth