I had a chain link fence.. before it was over with, I spent more time and energy keeping my dogs inside that fence than I did with the invisible. I have a pit, and an Aussie.. both were under a year old when I decided to get the invisible fence. We went through Dog Watch - I'd recommend it to anyone. My pit attempted to charge the line and succeeded once.. We called Dog Watch immediately and they scheduled us the next day and solved our problem. Dog Watch helps you train and comes to your house until you and your dog are comfortable with the results. The catch is the training, you HAVE to walk the dog through the motions twice a day for a few weeks. If you follow through with the training, you'll have no regrets. Great system, best thing I invested in. Would never go back to a chain link. It's coming up on almost a year.. I could throw a fresh steak over the fence, and neither dog will charge the line
. Train them right, and you'll have no problems.