We use the Dog Watch eFence to enclose our horde, and it works very well, so when we needed to modify behavior in the pack, we looked back to Dog Watch, and bought these. Big Leash Trainer
You can control up to two dogs with vibe, shock burst, or continuous shock. They have helped me to break them from barking at deer, and now chasing the deer is my focus. The dogs respond very well to a vibe warning, and when they get forgetful, a shock burst turns them around and heads them home. Rechargeable batteries and long range too.
The DogWatch guys are great fellows. They trained our dogs to mind the fence way back when we put it in, so we asked the trainer to come back out and train the dogs on the eCollar. They started minding the eCollar that same day.