JBL TopClean II

"Surface skimmer for aquarium filters • Automatically cleans the surface of the water, increasing the oxygen content in freshwater and saltwater. • Attaches easily to suction hose of external filter (fits 9/12 or 16/22 hoses). • Infinitely variable ratio of surface water to deeper water (adjustment spindle easily accessible from above). • Can be adapted to fit aquariums of over 35 cm high. • Unobtrusive design allows the surface skimmer to “disappear” in the aquarium. • Suction section floats, automatically adapting to the water level. "