These 7 electronic whistles were selling in the USA for around $35 each. I bought these from China outlets at various prices for around $10/each ($70). Why so many?
Different outlets had different descriptions, but as you can see, there are only 2 brands. It took a month for them to get here to learn that.
I will sell the lot (all 7) for $5.00
I used 2 of them to referee basketball outside during the pandemic. They were surprisingly LOUD, no problem stopping the game.
The battery lasts a surprisingly long time. 5 of them are new, unused. I no longer referee.