PetSafe Stay And Play Wireless Fence Stubborn Dog Extra Receiver Collar PIF19 14186 Educator Collars Both transmitter and receiver collar Choose the Type of Citronella Cartridges:Scented Both transmitter and receiver collar comes with a 3 year warranty The ET 300 mini remote trainer is best and great for training domestic and working dogs in parks and open fields up to 800m long distance signal range Owner’s Manual The receiver collar delivers a warning tone as your dog approaches the boundary zone before it gives a safe static correction through the contact points enough to get his attention and makes him go back to the safe zone