Essential In-ground Fencing System This electric dog fence system uses a buried wire broadcasting a radio signal to create a defined boundary zone for your dog, and includes a weatherproof receiver collar and a transmitter with power adapter If your dog gets close to the edge of the underground fence boundary, the weatherproof receiver collar will release a warning tone; if the dog keeps moving toward the boundary, the dog will receive a static correction via the collar Collar is comfortable and lightweight and includes 3 correction levels to adjust for your dogs sensitivity Kit also includes boundary zone flags, two CR 2032 lithium batteries, 500 feet of wire, 3 sets of probes for collar, test light, mounting hardware, splicing kit, and instruction manual with training guide For dogs 6 months and older, weighing 9 lbs. or more; collar fits neck sizes of 6 to 28 inches Expandable for multi-dog households 1-year limited warranty