Switch 0 / TEST (audible-loud)This setting allows you to hear the ultrasound at a audible level to check if the ultrasound speaker is working properly. Test switch is just like a converter, it converts the ultrasounds (inaudible to humans, but audible to rodents ) to sonic sounds (audible to humans). No ultrasound will be detected in this setting. | Switch 1 / ULTRA (inaudible)The speaker on the left will emit variable frequency ultrasound which is varying between 19kHz ~ 65kHz and above human hearing. So it's inaudible to human ear but audible to rodents. The ultrasounds is the default setting, it will be active too at Switch 2 and 3. | Switch 2 / DUO (inaudible)The rat prevention repellent will emit ultrasounds & impulse attack wave together. Inaudible to human ear but audible to rodents at this stage. Targeting rodents out! | Switch 3 / TRIO (audible-adjustable)DUO(ultrasounds & impulse) function is also active. In addition, the speaker on the right will play a loop of 10 kinds of audible sounds that rodents are most afraid of. It includes cat, dog, snake, owl and other natural sounds. The predators' sounds level can be adjusted. |