You can pick one up at the local pet store. Bass Pro Shop is even better. The quality is higher and some are waterproof. They will be in the hunting section. I love these. Some have a button for a warning so the Mistress doesn't have to shock all of the time. Of course, there is one for the intensity of the shock as well. I don't know that I'd put them on someone's neck. I've only worked with them on a man's balls.