Ultrasonic bird repeller 1,Scare the birds away a larger radius; 2,Applicable to airport 3,Effective control area:>2000Square Ultrasonic bird ... the scope of:>2000 M2Application1,It can be used to drives away all kinds of birds such as,Pigeons,Crows,Sparrows ... warehouse, cultural relic protection, etc widely. Product description According to the principle of bionics, the human invent the device which ...