4 Speed Adjustable Wind - Experience customizable cooling and comfort with the 4 speed settings of our rechargeable fan portable. From a gentle breeze to a powerful gust, each airflow is crafted to cater to your needs. Especially the 4th speed variable frequency wind can provide the closest natural wind. Ultra Quiet - The Blades design has been upgraded with new technology and high quality ABS, so this small desk fan advanced the sound 25% quieter than others. The min noise is about 30 db, max noise is under 50 db, suitable to use in working and studying. Flexible Adjustment - The battery fan has a head that can rotate vertically and horizontally. to adjust to find the most comfortable Angle to use it.