metal whistle with opener logo engrave .zinc metal material/ factory direct supply ... ,etc.7. function: used for sports meeting,police,referee,Army,childrens toy,and promotion gifts.8 sample:The sample is ... ,etc.7. function: used for sports meeting,police,referee,Army,childrens toy,and promotion gifts.8 sample:The sample is ... .10 packing: each packing or as your request. metal whistle with opener function