... as follows:1. material: iron,copper,aluminium alloy and plastic.2. size: optional3. pattern: 6-shape,1-shape ... key ring,lanyards,metal hooks and chain,etc.7. function: used for sports meeting,police,referee,Army,childrens toy ... as follows:1. material: iron,copper,aluminium alloy and plastic.2. size: optional3. pattern: 6-shape,1-shape ... each packing or as your request. metal whistle with opener function