PetSafe Stay + Play Wireless Fence

2 collars are included Keep your pet safe in your yard without burying wires! Charge the rechargeable Receiver Collar in 2-3 hours. The Transmitter communicates with your dog’s Receiver Collar and helps keep them in the designated area by first delivering a warning tone should they approach the containment perimeter and then by delivering a harmless stimulation should they proceed further towards the containment edge. The system is portable, so you can bring it along with you! An unlimited number of pets can be added to the system as long as they wear a PetSafe® Wireless Receiver Collar.