Straight waterfall box or a biological filter and falls. Extra wide spillway for greater water aeration. Pro 2000 waterfall box, no media 11.25 opening. Open swirl chamber for even and efficient water flow through the filter media. Mechanical and biological filtering for super clean water. Easily buried in ground to hide canister from sight. Clean once a year under normal use. Dimensions are 15 X 12 X 9 UPC Code = 025033024670
