BEFORE PLACING YOUR ORDER CONTACT US SO WE CAN CONFIRM AVAILABILITY AND OFFER YOU A DISCOUNT CODE. YOU MAY DO THIS VIA CHAT OR EMAIL [email protected] SEND US THE PRODUCT NAME AND WE WILL PROVIDE THE DISCOUNT CODE. WE PREFER CHAT TO GET RESPONSE. This electric fencing system is a reliable and cost-efficient pet containment system. The transmitter emits a harmless radio signal in a radius between 20ft to 850ft(selectable) around itself and the signal is detected by the collar. If your dog walks out of the signal boundary of the transmitter, the receiver will deliver warning beep sounds, vibration and shock to warn your dog until it goes back into the signal boundary. Besides, you can switch the transmitter to Dog Training Mode to train your dog via beep/vibration/shock modes. No wire needed and rechargeable features allow it portable for outside traveling to protect your dogs in limited space.