Complete bird control system combines both sonic AND ultrasonic audio to get rid of pest birds with a multi-faceted audio attack. The sounds confuse, disorient & intimidate pest birds, keeping them away. 4-speakers included for maximum coverage (see "Details") Message to pest birds is clear: "EMERGENCY: STAY AWAY!" State-of-the-art technology decoded, customer support available Fully customizable settings allow tailored programming Option to add 3 Visual Scares to package for added efficacy Ultrasonic covers up to 3,600 sq. ft., sonic covers up to 6 acres