Low noise 50dB oxygen pump. Suitable for outdoor aquarium, pond or fishing. Solar powered oxygen pump, no battery or plug required, economical and eco-friendly. 2 air stones and one connector. Built in 3.7V lithium battery 1800mAh 18650 to store power, thus the oxygen pump working at night as well. Easy to dual airflow with the included [Y] connector.Low noise oxygen pump of 50 dB. Suitable for outdoor aquarium, pond or fishing.