After riding for sixty years, I have made a few conclusions. I live in the Great Smoky Mountains. It is usually bank on one side and hillside falling away on the other. When a motorcycle leaves the road on the deep side, there is almost always no indication of his departure. He is down there somewhere and there are many reasons why he might not be able to crawl up to the road. Any area not visible from the road may leave the rider very lonely and often very helpless.
That leaves him yelling "help" until his voice gives out, and that is not very long.
So I wear a Thunderer around my neck with a bead chain. It can be heard inside most cars with the windows up!
This inexpensive little whistle may be central to being found. Or being stuck there.
It may save your life. Many whistle sizes and many finishes make a choice here both personal and pleasing.
Thanks ACME and EWHISTLES