This 3m Aquarium Oxygen Pump Air Hose is a must-have accessory for any fish tank enthusiast. With a 4mm diameter, it is perfect for use with air pumps and other aquarium accessories. Made from high-quality materials, this air line tubing is durable and long-lasting. It is easy to install and use, making it ideal for both novice and experienced aquarium owners. Whether you have a small or large fish tank, this air hose will help to keep your fish healthy and happy by providing them with the oxygen they need to thrive.