The Dymax Crystal Lily Pipe Set (12/16mm Dia.) gently directs filtered water into an aquarium, providing proper aeration and avoiding disturbance to the aquascape. Made of high-quality crystal quartz glass, this handcrafted set includes a built-in water surface skimmer to prevent oil accumulation and reduce CO2 loss. Available in 12/16 and 16/22 diameters, it comes with an outflow and inflow pipe, as well as four aquarium suction cups.