Havahart Wireless Radial Shaped Dog Fence System Creates a circular boundary extending from 40 feet to 400 feet in all directions from the controller Quick and easy to install in minutes with no need for trench digging Easy-to-read LCD screen on 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) Designed for any breed dog older than 6 months and weighing more than 8 pounds