Dymax Crystal Lily Pipe Skim 16/22mmDymaxs Crystal Glass Lily Pipe removes debris from the waters surface and allows filtered water to flow gently into the aquarium, providing proper aeration throughout. This glass pipe set comes with both the inflow and outflow pipes and a surface skimmer attachment. Highlights: Made of high quality crystal quartz glass Quality handcraft selection Built in water surface skimmer Increase water movement Prevent accumulation of oil on the water surface