Esky 300M Range LCD Remote Shock Control Pet Dog Training Collar with 100 Level of Vibration+ 100 Level of Static Shock RechargableBoth collar and remote are rechargable. No extra batteries is needed. Multichoice for dog training: It can provides a professional 100 level shock and 100 level vibration. Expandable: The system can be expanded with 2 receivers. Please search "EP-300R-B1" on Amazon to purchase. Convenience: Easy-to-read LCD screen shows the stimulation level. Over 3,000 different identity codes to prevent conflicts with other e-collars.