Whistle for an arrow

Everyone knows about Robin Hood and his friends. In one movie, they use whistling arrows to communicate between themselves. That's cool!
So, my son and I wanted to buy a whistle for our arrows. But there are only whistles available, that you put on the top of an arrow. If you hit a stone or a tree, it breaks. That's not cool...
After a day, my son had a solution. We need a whistle around the shaft of the arrow. To pin it, we use two peaces of tape. Cool again!

We hope you enjoy our whistle for an arrow and always be careful with weapons!

Thanks to FabLab Darmstadt and MakerSpace Darmstadt!