Maximize your dogs play area to give him more space to run or fetch his favorite tennis ball with the PetSafe YardMax Rechargeable In-Ground Fence. When using traditional in-ground fences your pet receives a warning tone or correction before they cross over the buried wired. With the innovative technology of the YardMax In-Ground Fence, your pet gets a warning tone or correction once they cross the buried wire to create a seemingly endless boundary. Inside this kit you will find 500 feet of wire to create up to a 1/3-acre area to keep your best friend safe and secure. With the purchase of additional wire, you can contain up to a 10-acre yard. This in-ground fence comes with 1 PetSafe YardMax Rechargeable In-Ground Fence Receiver Collar that fits dogs who weigh 5 pounds or more and adjusts to fit neck sizes between 6-28 inches. The collar has a tone-only mode plus 5 levels of adjustable correction depending on your dogs temperament. Two exclusive tests, the ReadyTest and the PerfectFit test help you know the status of your pets receiver collar and ensures a proper collar fit. This system includes a unique run-through prevention to help keep your dog from running through their set boundary. If they attempt to run through, the static correction level will increase to encourage your dog to stay inside their safe play space. If you have more than 1 pet at home, simply purchase as many additional compatible receiver collars as you need so all your pets can use the same system. With just 2 short weeks of training, your best friend will enjoy roaming and exploring their new play area!