NEW INNOTEK® UltraSmart In-ground pet fencing systems receivers set a new standard. The difference is in the sleek, streamlined contoured comfortable fit collar -- 30% smaller and lighter than other containment receivers. The Innotek Ultra receivers are Superior, Smarter, and Safer than any other systems. Technology makes the difference. The Ultra systems receivers are the Only systems which incorporate Lithium Ion Technology. The receiver that is incorporated into the Collar. The receiver that is contoured to your dogs neck. The Only receiver which performs a self diagnostic. The Only receiver which automatically tests for proper collar fit. The Only receiver which provides instant feedback on battery strength.