Electric Dog Fence&trade; PetSafe YardMax Containment System Professional Grade Complete DIY Installation Kit (4 to 6 Acres Coverage Area) (3 Dog Kit) Number of Dog Fence Collars = 3 (Unlimited Dog Capacity with Purchase of Additional Collars) Coverage Area = Up to 6 Acres (2500 Feet of 14 Gauge eXtreme Dog Fence Brand Dog Fence Wire) Lightweight Dog Fence Collar (3 Ounces) is Rechargeable, Waterproof, and Has 5 Correction Levels to Choose from. Each Collar is Set Individually, Per Each Dog's Temperament and Threshold for Discomfort. Unique Fence System Allows Your Dog(s) to Get Right Up to the Boundary Wire, Before Getting A Warning and Correction. This Provides 30% More Play Area for Your Pet(s) to Play in. One Year Manufacturer Warranty, Professional Technical Support, Fast, Free Shipping!