Respect for the environment 】Powered by solar energy, no battery or electricity needed, energy-saving and environmentally friendly. Meet your needs 】With small size, low noise and large air volume. You can fall asleep normally while you work. 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.