Working principle: This is a pest repeller using ultrasonic technology, playing the high-fidelity electronic sound of natural predators of birds, to achieve the effect of repelling birds with human characteristics, environmental protection, no pollution, high efficiency and more.Solar powered: This ultrasonic repeller is powered by solar panels, no messy electric cables, low power consumption , Environmental Protection. Cost effective, it can be used on a maximum area of 500 m2.PIR motion sensor: The ultrasonic repeller is equipped with a PIR motion sensor, fully automatic control, when a movement is detected in a certain area, the system emits ultrasonic frequency.Adjustable frequency: The ultrasonic frequency is between 12KHz and 30KHz and can be adjusted. By adjusting the ultrasonic frequency, different animals can be repelled, such as birds, dogs, foxes, rats, squirrels, etc.Multiple application scenarios: Weatherproof, all weather conditions, it is suitable for field use and effectively protects your crops or garden from damage. It can be used to repel birds in large fields and fruit forests, but it is also suitable for bird repelling operations in other areas such as electricity, airports and warehouses.