This ultrasonic pest repeller produces ultrasound at constantly changing frequencies to frighten away animals including unwanted cats dogs foxes and rodentsr r the sound waves and bright light activate when an animal enters the pir sensor range the coverage can be easily adjusted using the sensitivity dial up to a maximum of 500 square feet r r it is simple to use and comes with an aluminium ground spike and usb charging cable for when there has been little sunr r adjustable frequency an