Features: Solar-powered oxygen pump, no battery, and plug required, economical and environment friendly. Comes with 1 soft hose, 2 air stones, and a connector. Built in a 3.7V 1800mAh 18650 lithium battery for storing energy, thus the oxygen pump works at night as well. Easy to double the airflow with the included "Y" connector. 50dB low noise oxygen pump. Suitable for outdoor fish tanks, fishponds,s or fishing. Specifications: Material: ABS Solar panel2.5W, PET laminated Battery3.7V 1800mAH Product working voltage range3.0V4.25V Discharge protection voltage3.0V Over charge protection voltage4.25V Max. Current: 450mA Noise: 60dB Waterproof: IP64 Min. Air Flow: 0.6L/min Working Time: Approx. 20 hours