Esky 1000M Rechargeable LCD Multi-Dog Remote Control Training Collar System with Multiple Mode Combinations RECHARGEABLE:Both 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.