This battery powers the High Tech Pet Humane Contain® HC-8000 Plus and X-10 Electronic Dog Fences. In the event of a power outage, the battery takes over, keeping your dog safely contained for up to two days. When power is restored, the battery is automatically recharged. There’s no need to worry about your pooch escaping during power failures, and there’s no need to bother changing or recharging batteries. It’s all completely automatic. This is a must-have electronic dog fence accessory.