I only use one if I think I will be away from my crew bag/crew/trailer at a hold while the temps indicate it, or if I plan to ride with it (which I hardly ever do). I like the one I bought last year at convention from Action Rider Tack because it has a draw string that you can tighten and loosen while mounted very easily. I hate fooling with stuff when I am at a ride..got to be easy, or I won't do it.
It is in their catalog..called a "C-Ya Rump Rug". It is polar fleece underneath a nylon fabric...seems to have worked well the few times I have actually used it.
