The Barrier Transmitter, disguised as a rock in your landscape, sends a circular radio signal to your pet's Receiver Collar.  When your pet enters the Barrier Area, he'll hear audible tones from the Receiver Collar followed by a safe, progressive Static Correction.  The correction is delivered through the Contact Points of the collar that touch his neck.  He'll quickly associate the correction with the area you've declared off-limits. Add an unlimited number of Pawz Away® Extra Outdoor Pet Barriers and Pawz Away® Extra Receiver Collars to fit your needs.