31. The anti-burglary system transmits ultrasonic waves, not audible to human ear, to detect the movement of an object. 32. The system tranmits ultrasonic waves, not audible to the human ear, to detect the movement of an object. |
31. The anti-burglary system transmits ultrasonic waves, not audible to human ear, to detect the movement of an object. 32. The system tranmits ultrasonic waves, not audible to the human ear, to detect the movement of an object. |