Description: Solar oxygen pump with built in a 3600mAh lithium battery for storing energy, thus the oxygen pump working in the night as well. Just put the solar panel in a sunny spot and it starts automatically. Suitable for a small to medium sized pond, outdoor fish tank or water reservoir, etc. Features: [Solar Energy] The use of solar energy makes it environment-friendly, portable and easy to install with no need for wiring, no operating cost and maintenance free, and solar power is much safer for your kid. [Battery Backup] Built in a 3.7V 3600mAh 18650 lithium battery pack for storing energy, thus the oxygen pump working in the night as well. [low Noise] Stable silent oxygen pump with less than 60 dB low noise and 0.5-0.9L/min air volume, suitable for many types of containers. [Evenly Air Distribution] There are 3 working modes can meet your different demands, and two air flow outlets make the air distribution more even and pervasive. [Adjustable Angle] The solar panel angle can