"Mad Dog Go Away" is a dog deterrent which can help keep a distance from angry dogs. Try it now! "Mad Dog Go Away" produces high frequency sound and ultrasound from a piezoelectric disc of device. The sound pressure level is below the threshold levels of pain for dogs. Instead, the frequency range is 15 ~ 25 kHz that dogs can hear 60 Hz to 60 kHz. Dogs are startled from a focused state to react in a different manner, usually avoidance of the strange, distasteful and sudden sound of this tool.