Tiger Cub Bark Control J-1302 is designed by sound control and fitted on the wall. When the dog barks the sound arouse electric circuit. Ultrasonic wave will emit from product it discomforts dog but has no harm to dog. Such ultrasonic wave is heard by dog but not by people. After several repeated action the dog know the extra sound has been caused by his bark so establish a conditioned reflex. Afterward he would not bark without reason; Adapt integrated circuit when continuous 3 barks will arouse circuit but one bark or sudden sounds from environment could not cause unit emitting ultrasonic wave. Bark loud level different distance away from unit noise of environment can affect unit working correctly. So it's not certain that continuous 3 barks can intrigue unit but its effect is available.