If you search for "training collars for stubborn dogs" on Google or Bing, almost every first page will be filled with remote dog training collar reviews
While not all distance training collars are shock collars, the vast majority are.
Even those who promise a pain-free training experience use aversion techniques.
In other words, shock, startle, or frighten your dog into stopping the unwanted behavior rather than rewarding him for doing what you want.
You'll notice that the latter are aversion-based collars