You and your dog will appreciate the safety and security of this Havahart Radial-Shape Wireless Dog Fence. Havahart Wireless is the leading innovator of digital wireless fence solutions. This system is designed to provide maximum freedom and safety for your dog. You create a circular boundary that can extend from 40 feet up to 400 feet in all directions with technology housed in a sleek, compact controller. There are no wires to bury or break, no back pains from digging, and no wasted money on trenching -- just a fast and easy setup that creates freedom for your dog to roam! The easy-to-read LCD screen on the controller lets you set the exact distance of your fence boundary and customize correction levels. Up to two collars can be used with the wireless system (1 collar included). This system is designed for any breed dog older than 6 months and weighing more than 8 pounds. Other outstanding features include one extra set of rechargeable collar batteries (instead of having to replace them) and the best warranty in the wireless dog fence industry.