Let all of your pets enjoy more outdoor freedom! Add an unlimited number of pets to your YardMax® Rechargeable In-Ground Fence in-ground system with this extra receiver collar. YardMax® maximizes the amount of yard space for your pet to play freely in. When your pet nears the boundary, the receiver collar will give an audible beep, followed by a static correction to remind your pet to stay within the boundaries. Your pet will be enjoying your entire yard safely in no time! Click here if you need professional installation and boundary training.