This aquarium check valve is designed to prevent backflow in air tubing systems, making a consistent and of oxygen to your fish tank. Its compact and Sturdy design makes it an essential accessory for maintaining water and protecting your air pump from potential damage caused by reverse water flow. Features -Color:Transparent -Material:Plastic -Size:4.00X2.30X2.30cm/1.57X0.90X0.90in -Prevent backflow: quick prevents water from flowing back into the oxygen pump, protecting it from damage and making longterm stable use -Maintain aquarium balance: avoids water backflow into the fish tank, maintaining balance and enhancing the viewing use -Easy installation: suitable for various oxygen pumps, easy to install, providing water flow control for your aquarium -Energy quick: precision design reduces energy consumption and operates quietly, creating a peaceful and comfortable viewing environment -Sturdy material: made of plastic, it withstands longterm, resists aging, extends service life, and reduces replacement frequency Package list: 20 x aquarium check valve