A strong ultrasonic signal frighten animals. Thus, animals can not get used to the sound, and the effect of repellent is stronger, frequency from 13.5 to 23.5KHz.

the strong flashing will scare the animals away, especially at night time.

Switch from 0 to 3 for different working modes 0: off

1: working 5 seconds, interval 50 seconds
2: working 5 seconds, interval 2 minutes
3: working 5 seconds, interval 5 minutes

Batteries life varies with the setting of the ultrasound. Choose different working modes due to different needs of customers.