If you use it to train your dog, then you are a dummy, impatient little bitch who can't have little effort to teach your dog some rules 'n as such, but if it really doesn't help, he knows the rules but still breaks them, then you don't need a shock collars, just a fence which is deep enough in the ground so your dog wont dig under it 'n put something above the fence too, high enough so he/she wont jump over...
There are other ways to do that or protect your dog from running off, I would wanna see if dog turns into like "human noid" dog which does the things what humans do for them, then that would be embarrassing.
A shock collar is made to hurt pets in order to teach them not to go past a certain point or for other reasons. By the definition it is a weapon, however non-lethal. Sort of like a taser. Cops must be tased themselves so that they fully understand what that weapon does before using it on someone else. Before using a shock collar, follow standards and use this non-lethal weapon on yourself before you decide to use it on others. Even if others include your pets.
Quotes from the Huffington Post:
That should be reason enough not to even if it happened to be faulty.
Also: Shock collars are not only physically unhealthy for dogs but mentally aswell: