John,
I can't help you much with where it came from or how to install one on a bicycle wheel but I'll vouch for how well it works. There's one on the front wheel of my trike, 12" scooter style wheel, and that little guy has some stopping power. The rear coaster brake went out and I rode the trike around as a plant bike for a long time and many miles with only that small band brake on the front wheel. It shows little signs of wear and still grabs tight. I'll examine it a little closer tomorrow when I'm back to work and see if I can suggest a way that it could be adapted to a spoked bike wheel. By the way, if you don't know where to find one, where did you get the picture? Curious.
Tom