I put deer whistles on all my vehicles, including my F6B. All I can say is that I see fewer animals at night with them than without them. Before I put the latest batch on my daughter's car, I blew them in the house. The dog and the cat went nuts, so they must do something. I figure they might work sometimes and not always. And they only work at speeds of 40 mph and higher. But they are so cheap that there's no reason not to use them.