Features: Solar powered oxygen pump, no battery and plug required, economical and environment friendly. Comes with 2 soft hose, 2 air stones and a connector. Built in a 3.7V 1800mAh 18650 lithium battery for storing energy, thus the oxygen pump working in the night as well. Easy to double air flow with the included Y connector. 50dB low noise oxygen pump. Suitable for outdoor fish tank, fishpond or fishing.