Expand your SportDOG Brand® In-Ground Rechargeable Electric Fence system with our Add-A-Dog collar! Featuring an upgraded collar with a rechargeable lithium-ion battery that charges in just 2 hours and lasts 1-2 months per charge, this is the ultimate add-on for multi-dog families. The Anti-Linger Feature ensures that your dog won't run down the Collar Receiver battery in the warning zone, giving you peace of mind. With 7 levels of static stimulation, you can customize the experience to match any dog’s temperament. It also includes a vibration/tone warning for additional training flexibility. Plus, with DryTek® technology, this collar is waterproof and submersible up to 25 feet. Keep your dogs safe and your mind at ease with this efficient, reliable, and high-quality Add-A-Dog collar.