Lily Pipe Set consists of 2 major parts: the inflow and outflow pipe. These pipes are used to increase water movement in lower parts of the aquarium where water can easily become stagnant. Powerful flowrate is used to create strong currents. The feature of the outflow pipe is to create powerful flowrate for stronger currents without disturbing the aquascape within the aquarium. These are great for the flora and fauna that prefer high flowing currents. Despite the strong flow being created a powerful flowrate is still suitable for both growth of aquatic plants as well as coral reef. Total inlet pipe length: 35.5cm. Total Outlet Pipe Length: 34.5cm. Inlet depth: 30cm. Outlet depth 11cm. U Pipe Spacing: 4.8cm. Inner diameter: 1.2cm. Lily pipe holder included.