【Environmentally Friendly】 Powered by solar energy, no battery or electricity required, energy-saving and environmentally friendly. 【Meet Your Needs】 With small size, low noise and large air volume. You can fall asleep normally while working. 【Good Quality】 Made of high-quality ABS, built-in high-quality lithium battery, sturdy and durable. 【High-Capacity Battery】 Built-in 3600mAh high-capacity battery, it can work continuously for up to 14 hours once fully charged. Meanwhile, this air pump can be recharged by DC power with a USB cable. 【Advanced Design】 The technologically advanced design provides smooth and quiet operation. At the same time, it has a stylish blue appearance.