Z824Z824 24" FLO-THRU TRENCH SYSTEMZurn Z824 24" [610 mm] wide pre-sloped trench drainage system. Glass-filled polyester fiberglass drain channel with 1/8" [3.18 mm] per foot bottom slope. All sections are modular 5-foot [1.52 M] lengths with interlocking ends. Complete with heavy-duty, Dura-Coated steel frame at surface, combination anchor tabs/leveling devices at appropriate locations and heavy-duty cast iron grate.