https://www.amazon.com/gp/product/B00EVIL9WK
Picked it up for Xmas. I'll let you know how it works when the ice is out.
I mainly wanted it for some bit of idea when I am being overtaken. I'd still turn my head to see before I turn, but I've gotten surprised a couple times when folks I know came up from behind and hit me with the airhorns.
