Esky Rechargeable Remote Dog Training Shock Collar with Vibration (For 1 Dog) Easy to operate as ABC 2-dog compatible. Another collar can be easily added to this system following the manual. Purchase our collar (model: R500-C) to train two dogs simultaneously Ergonomic remote control. Remote powered by a 6F22/9V battery (INCLUDED) Delivers effectively harm-free vibration and static shock correction Waterproof receiver powered by a built-in Li battery (rechargeable)