If you are going to use one of these collars you have to get the right one.you need one with a beeper function so the dog associate s the beep with a shock or if he runs beep him if he takes no notice then you give him a shock starting on the lowest level if no reaction knock it up one notch until the dog responds so basically the dog will associate the beep with a shock so he will return as he does not want a shock I use a Canicom 500 for 2 years now although I do not use the shock side of it I use the beeper only and it was the best Money I spent but this is my opinion and every one will hav