Create a larger play area for your canine companion with the PetSafe Stay & Play Wireless Dog Fence Replacement Transmitter! This extra transmitter is compatible with your existing Stay & Play Compact Wireless Fence， Stay & Play Wireless Fence for Stubborn Dogs， Stay & Play Wireless Fence with Replaceable Battery Collar or Wireless Pet Containment System. Adding this transmitter to your wireless fence system can create an additional ¾-acre circular boundary area for your pup to play and roam freely. The transmitter’s LCD display shows the diameter of the boundary area， making it easily adjustable. It also has warning indicators to let you know if there is an error with the fence. And since it is completely portable， you can bring it with you camping in an RV or to a vacation rental， so your buddy has a safe place to play while you travel. You can also purchase some PetSafe Boundary Flags (sold separately)， so your dog can learn the boundary area at your vacation destination. Simply place the transmitter inside and plug it into an outlet. This kit does not come with an extra receiver collar， so make sure every furry friend in your family has his or her own compatible collar before heading out to play!