20Pcs Black Plastic Aquarium Air Pump Check Valves Non-Return Valve for Fish Tank Accessories

• 【Quality Guarantee】Guarantee refund, if you have any dissatisfaction on the quality of goods, please contact us, we are willing to send you a new goods or a full refund.Package Included: 20 x Water Check Valve。
• 【High Quality】Made of premium plastic material, our check valve has a good stability and durability.
• 【Non-Return】It prevents water backflow from damaging the front-end air pump or other product equipment when the air pump is placed below the water After adding the stop valve, the air pump can be placed the water or below the water surface, and there is no danger of water returning when the air pump is powered off and stopped working.
• 【Protect Air Pump】The water is reversed due to inside and outside pressure difference when oxygen filling pump is suddenly stopped, and the oxygen-filled pump is damaged and the water in the cylinder overflows.
• 【Easy Installation】Lightweight, thus it is easy to install and use.Length: Approx. 5.5cm/2.2in。

Specification: Material: plastic Color: black Length: Approx. 5.5cm/2.2in Suitable for air inlet / outlet Gauge Tube of 4mm. Package Included: 20 x Water Check Valve Notice: Each outlet needs to be installed one. The double-headed air pump needs two stop valves to prevent the water in the hose of the aeration pump from flowing back to the machine and damage the front-end air pump or other product equipment.