This is the simplest way to erect an invisible, indoor pet barrier without extensive installation or renovation costs, or placement of physical barricades that have to be managed by hand or removed when guests arrive. The system comes with two transmitter disks that can be placed anywhere that dogs are not allowed, such as on a countertop, behind a trashcan, underneath a couch, or at a particular doorway. The transmitter can be set to generate an invisible electronic barrier from 2' to 12' in diameter at the touch of a switch. A special receiver collar worn by the dog emits a brief warning sound followed by a non-harmful electric stimulus that startles, but does not cause pain to, the animal when the receiver approaches the radius of the transmitter. As the dog learns that a particular area is not to be approached, the audible warning tone will be enough to discourage the pet from proceeding. The collar is 2" wide and will fit a range of dogs from 10 lbs. to 75 lbs. Additional collars and zone transmitters are available separately below. Each zone runs on three AA batteries for six months of use before requiring new batteries. Transmitter: 5" Diam. (7 1/4 oz.) Collar: (1 1/3 oz.)