PondMaster 500 dual pond filter. Low profile, less obtrusive in the pond. Features a larger filter for less cleaning. Offers mechanical, chemical, and biological filtration. Filter media is easily changed. Quick disconnect for easy removal from pump. Can be used with many submersible pumps. 9" x 9" filter box with removable filter cartridge. For use with pumps up to 500 GPH (gallons per hour).