Must have. It will fix your family fights about who's turn it is to take the dogs out. Just open the door and let the dogs go do their thing. Don't forget to read the instructions how to set the collar up high or down low. It sounds mean but it keeps the dogs safe by correcting the dogs to stay in their own yard with out you tugging on a leash around the dogs neck. If you can get past the first few times the dogs do try to go out side the wire fence it will not happen often after that first few times. We put the wire right on top of the warm or frozen ground, snow, rain. We keep the transmitter out side under a big bucket to keep it simi dry.