"Laguna PowerFlo Round Filter provides complete mechanical, biological and chemical filtration. The result is clean and healthy pond water and a significant reduction in the frequency of clogging in water pumps and fountain heads. Its unique shape is ideal for a number of applications including whiskey barrels, patio & deck basins, and outdoor & indoor ponds up to 500 US gal./1892 L. A large surface area is designed for superior filtering capacity. The unit can be fitted with a Laguna PowerJet fountain pump which is required to circulate the water. Two Laguna pond lights (sold separately) can also be anchored to the unit to create colourful light displays. The filter includes two filter pads (mechanical/ biological & chemical). Diameter: 19""/48 cm. Height 4-1/2""/11.4 cm. "