The Premier Pet In-Ground Fence keeps your dog safely in your yard with a customizable barrier that includes coverage up to 1/3 acre and is expandable up to 5 acres with the Premier Pet Wire and Flag Expansion Set (GRFA-500). The barrier can be customized to contain your dog in your entire yard, a partial area of your yard, or to prevent access to certain areas, such as a garden or pool. The included waterproof receiver collar has a nylon strap that is adjustable up to 26", making it a great fit for both smaller and larger dogs. A low battery indicator on the collar will alert you when the collar battery (GAC11-16351) should be replaced. The collar has 1 level of tone only for training and 4 adjustable levels of static correction so that you are able to choose which level works best for your dog. A safety time-out feature will stop correcting after 30 seconds should your dog get outside of the boundary zone. You also have the option of adding an unlimited number of dogs to the system with the Premier Pet In-Ground Add-A-Dog collar (GIG00-16920). Give your dog freedom to play and yourself peace of mind with the Premier Pet In-Ground Fence!