The clay slingshot ammo ball is made of biodegradable soil. You can use it up and discard it outdoors without worrying about environmental pollution. The size is 9mm-10mm(3/8inch),a great learning tool for kids to practice shooting ability and suitable for hunting or shooting little hamsters and small birds. Other Uses: It can be used to cover the soil of flowerpots to prevent the dust from flying and to add beauty.