According to US Baby experts:

The most annoying thing in summer is the ubiquitous mosquitoes, which can easily make healthy baby fall ill. Traditional mosquito repellent methods are harmful to human body. US Baby experts recommend the convenient and safe US Baby electronic repellent device, which is variable in frequency from 5,000 to 20,000 hz. It can more effectively repel various mosquitoes without harm to human body and side effects. Three-section timing mosquito design (2h, 4h and 8h) is energy-saving and convenient with the effective range of1 to 3 meters and the battery life is about 200h. With the strategically designed LED lighting device, it can be used as a small flashlight.