I spend a lot of hours running alone. As a woman, there is always a fear that someone will want to do me harm. I bought the Tandem Sport Runner Defense Spray (pepper spray) for those times I wanted to run alone and feel safer.
I sprayed this once, to see if it worked and the spray came out about 7 feet. Certainly that's closer than I would want anyone to get, but it's better than being left unprotected. I do not know about how noxious the spray is (thankfully I was standing upwind during my test fire), but have no reason to believe it would do anything less than advertised (burn for at least an hour).
The holder is convenient. There is a loop you can either place your fingers through to hold it while running, or you could put a strap on a hydration belt or fanny pack through the loop to free up your hands.
I feel safer when running with this product. I would recommend anyone that runs alone, particularly women, to purchase this.