We purchased a Dog line system 18 months ago We have a 7 acre property Mid North Coast NSW 3 kelpies and one super busy 100klm/hr road along the North boundary - Dog line has been easy to implement and we know the dogs are safe - without having to be chained up We have just ordered a new collar for our latest puppy addition and the team at Dog line have been extra helpful pulling up our file to work out which collar we needed to get we rely on and trust the Dog line system for our 4 legged friends and highly recommend it to others wanting a secure yard for their dog