Ultrasound nausea

Could not pass by! Super gadget. For only 30 bucks, you can ruin the life of your neighbor, boss, foe ... This simple object acts quite simply: it creates a certain set of high-frequency ultrasonic waves (9 volts in total). The manufacturer promises to provide headaches, sweating and the urge to vomit. I want to buy, I will test - I will write it off.

Found here