Features:-The ultrasonic frequencies it produces can effectively damage the nervous and auditory systems of rodents, and are variable, preventing rodents from developing "adaptation" and "immunity" to fixed frequencies.-It is non-toxic, odorless, non-radioactive and completely harmless to humans and pets.-It has a working area of up to 1,290 square meters, effectively protecting your entire living space, including bedrooms, kitchens, basements, garages, attics, and more.-There are 3 modes, mode 1 (blue light), variable frequency ultrasonic 22k-36kHz, fixed frequency 25kHz, suitable for daily use; mode 2 (green light), variable frequency ultrasonic 22k-36kHz, suitable for night use; mode 3 (red light), PIR sensor, variable frequency ultras.