Humane Contain Rechargeable Electronic Fence Collar works with the Model X-10 Electronic Dog Fence to provide state-of-the-art pet containment. It also has an on-board ultrasonic transmitter to control optional accessories including Power Pet fully automatic pet doors, Sound Barrier and Yard Barrier Sonic Fences and Radio Mat Electronic Scat Pad. No need for your dog to wear multiple collars. This one does it all. You can add as many RX-10 collars as you like to your Humane Contain X-10 Electronic Fence to contain any number of dogs. Whether you use the RX-10 for dog containment only or as the controller for a complete electronic pet care system, this collar brings you state-of-the art technology in an extremely slim, lightweight package designed for maximum pet comfort. Rechargeable lithium-ion battery never needs replacement. (Model CRX-10 charger sold separately). This collar is fully waterproof and packed with advanced features, including High Tech Pets proprietary Pulsed Proportional Stimulus technology, waterproof audio speaker produces loud and clear progressive training tones for quicker boundary training. Built-in battery and stimulus tester. Dual radio receivers provide Omni-directional reception for consistent field width, regardless of the direction your dog is moving. Solid copper stimulus probes resist rust and corrosion and provide the best electrical conductivity.