When I tell you this product works- believe it. Our Great Pyr (know for running) would not stay home. We tried a few other options before buying this. We never even needed the shock mode bcus he was terrified of the beeping noise alone. It comes with step by step instructions, but you find what works best with your pet. It was well worth every penny for us! Our GP became familiar with his “beep” perimeter and doesn’t even cross it or get close to it in fear he’ll hear that beeping. It’s great! We have 40 acres and only have the perimeter set to 545sq ft and it’s sooo much space for him to still roam. It goes up to like 1200sq ft I believe so definitely great for those on large acreages.