A Dogtra Underground Dog Fence like the rest of thier pet products is designed for the sporting dog in mind. Thier system are made to be tough and durable and comes with awesome features for the sporting dog. The Dogtra Underground Dog Fence is rechargeable with a 2-hour rapid charge and is easy to add additional Collar for mulitple dogs. Dogtra takes pride in the development of user-friendly controls. A pet owner won't feel overwhelmed by over complicated controls to do simple tasks. The Dogtra Underground Dog Fence has the ability to containment an area of 40acres allowing your pet ample room to run around. If your dog needs the ability to explore it's surrounding and have the freedom to run around then a Dogtra Underground Dog Fence is the system for you.