The Big Cheese Sonic Mouse & Rat Repeller

The Sonic Repeller from The Big Cheese® produces powerful ultrasound at constantly changing frequencies which are too high for humans, dogs or cats to hear, but which are within the hearing range of mice and rats. Each unit protects an area of at least 37 square metres (400 square feet) from infestation by mice and rats. Drives mice and rats from the home.
 
With halo-red LED and TEST-button features to enable quick checks in-situ.