The Glass Lily Pipe Inflow (13mm) is an aquarium filter accessory used to create gentle surface water movement, oxygenation, and filtration. This lily pipe is made of smooth and clear glass, and has a 13mm size outlet. It is designed to be placed at the surface of the water, and works by drawing water in from the surface and pushing it downwards, distributing oxygen and filtering debris. The lily pipe can be used in both fresh and saltwater aquariums and is easy to install and maintain.