The In-Ground DELUXE Radio Fence is ideal for small to large yards, and even in areas with accumulations of snow, ice and heavy rain (transmits up to 25 acres). A transmitter plugs into a standard outlet and emits a radio signal that travels along an underground wire. A DELUXE Ultralight weight receiver is worn on your pet's collar which picks up the radio signal and alerts your pet as he nears the underground boundary. If he continues toward the boundary, he will receive a mild progressive correction, if your dog attempts to run through, the correction level increases until he turns back.. It is designed to startle, not punish. The range of the signal (i.e. the distance from the boundary wire to activate the receiver) can be adjusted from a few feet to 30 feet by adjusting the transmitter. Once your pet is properly trained he will learn to stay in the boundaries designate Radio Fence.