My FIL has it. We tested it out when he first got it by me taking off on the UTV around the county roads. It doesn't work quite as well as advertised, but for the money still works decently well. He lets his dog out unsupervised into his yard that isn't fenced (
) sometimes and I think it has a function that if the dog gets outside of a certain range it sets an alarm off on the house - it just so worked out that the range is about the size of his 5-6 acre place. That seemed to work pretty good.