Made of high quality PVC, sturdy, durable and long service life. Made of high quality PVC, sturdy, durable and long service life. When the position of the air pump is lower than the water surface, to prevent water backflow damage to the front end of the air pump or other equipment of the product, after adding the shut-off valve, the air pump can be higher than the surface of the water Used as an oxygenation pump due to the pressure difference between inside and outside when it suddenly stops working, causing the water flow to be reversed, damaging the oxygenation pump, and causing the water to overflow from the cylinder to form a strut Using the pump to air is very easy to handle and use to prevent water from entering the pump of the machine. There is no risk of water backflow when the air pump is turned off and stopped working, it’s the small protector of the gas supply installation.