Material: The steel ball is made of high quality carbon steel. WIDELY APPLICATION - Ideal use for outdoor hunting, entertainment, competition and fitness catapult, and attention training.   WARNING - It is prohibited to use this product in anyway that doesn't conform to local, state and federal laws and ordinances, this is not a toy, Children need use under the supervision of adults. Note: Although the carbon steel ball has high hardness, it has poor corrosion resistance. Please use a storage box to seal it when not in use to prevent rust.