Lewisia 2.5W Floating Solar Air Pump Battery with Air Hoses and Bubble Stone Pon

【Check Valve】— When the pump is on, the check valve opens, allowing the pressurized air or water from the pump to flow out and circulate throughout the pond, providing oxygen to. Auto Off Without Water — There’s a Water Level Sensor on the back of the solar panel so it shuts off automatically when the water is dry.